Method of manufacturing display device

ABSTRACT

To provide a method of manufacturing a display device having an excellent impact resistance property with high yield, in particular, a method of manufacturing a display device having an optical film that is formed using a plastic substrate. The method of manufacturing a display device includes the steps of: laminating a metal film, an oxide film, and an optical filter on a first substrate; separating the optical filter from the first substrate; attaching the optical filter to a second substrate; forming a layer including a pixel on a third substrate; and attaching the layer including the pixel to the optical filter.

TECHNICAL FIELD

The present invention relates to a method of manufacturing a displaydevice having an optical film that is formed using a plastic substrate.

BACKGROUND ART

In recent years, a technique of forming a thin film transistor (TFT)using a semiconductor thin film (with a thickness of from approximatelyseveral nm to several hundreds nm), which is formed over a substratewith an insulated surface, has been attracting attention. The thin filmtransistor has been widely applied in various electronic devices such asan IC and an electronic apparatus. In particular, development related tothe thin film transistor as a switching element for a liquid crystaldisplay panel or a light emitting display panel has been carried outhurriedly.

In a liquid crystal display panel, a liquid crystal material issandwiched between an element substrate and an opposing substrate havingan opposing electrode that is arranged opposite to the elementsubstrate. On the element substrate, TFTs using amorphous silicon orpolysilicon as their semiconductors are arranged in matrix, and pixelelectrodes, source wirings, and gate wirings each of which connects toeach TFT are formed, respectively. A color filter for performing colordisplay is formed either on the element substrate or the opposingsubstrate. Polarizing plates are arranged on the element substrate andthe opposing substrate as optical shutters, respectively, to displaycolor images.

The color filter of the liquid crystal display panel includes coloredlayers consisting of R (red), G (green), B (blue), and a light shieldingmask (a black matrix) for covering gaps between pixels, and extractsred, green, and blue lights by transmitting light therethrough. A lightshielding mask for the color filter is generally made from a metal filmor an organic film containing a black pigment. The color filter isarranged at a position corresponding to the pixels, thereby beingcapable of changing the colors of light to be extracted for each pixel.Note that, the position corresponding to the pixels indicates a portionthat accords with a pixel electrode.

In a light emitting display device, there are a colorizing method byarranging light emitting elements that emit red, green, and blue lights,respectively, in matrix; a colorizing method by utilizing a color filterwith use of a light emitting element that emits white light; and thelike. The colorizing method by utilizing the color filter with use, ofthe light emitting element that emits white light is similar to acolorizing method for a liquid crystal display device using a colorfilter, in principle (see patent document 1). Patent document 1:Japanese Patent Application Laid-Open No. 2001-217072

DISCLOSURE OF INVENTION

Conventionally, a color filter used for a liquid crystal display devicehas been formed on a glass substrate. Therefore, there has been aproblem in which the color filter formed on the glass substrate and theliquid crystal display device using the color filter have poor impactresistance properties. Also, when the thickness of the glass substrateis reduced to reduce the thickness of the liquid crystal display device,the substrate is likely to be cracked, which results in reduction inyield.

Further, since the glass substrate does not have flexibility, it hasbeen difficult to form a color film on a display device having a curvedsurface.

A colored resin and a pigment dispersing resin have been generally usedas a raw material for the color filter. In order to cure these resins,however, a step of heating at constant temperatures is required.Therefore, it has been difficult to form the color filter on athermoplastic substrate.

According to the above-mentioned problems, it is an object of thepresent invention to provide a method of manufacturing a display devicehaving an excellent impact resistance property at high yield, that is, amethod of manufacturing a display device having an optical film that isformed using a plastic substrate.

According to one aspect of the invention, there is provided a method ofmanufacturing a display device that includes: a first step of laminatinga metal film, an oxide film, and an optical filter on a first substrate;a second step of attaching a second substrate to the optical filter; athird step of separating the first substrate from the optical filter;and a fourth step of forming a layer including a pixel on a surface of athird substrate after the first to fourth steps, and attaching theoptical filter to another surface of the layer including the pixel.

According to another aspect of the invention, there is provided a methodof manufacturing a display device that includes: a first step oflaminating a first metal film, a first oxide film, and an optical filteron a first substrate; a second step of separating the optical filterfrom the first substrate; a third step of attaching a second substrateto the optical filter; a fourth step of laminating a second metal filmand a second oxide film on a third substrate after the first to thirdsteps, forming a layer including a pixel on a surface of the oxide film,and attaching the layer including the pixel to the optical filter; and afifth step of separating the second metal film from the second oxidefilm, and attaching a fourth substrate to another surface of theseparated second oxide film.

Note that, after carrying out the first and second steps, the third stepcan be performed. Also, after carrying out the first and third steps,the second step can be carried out.

Display devices such as a liquid crystal display device, a lightemitting display device, a DMD (digital micromirror device), a PDP(plasma display panel), a FED (field emission display), and anelectrophoretic display device (an electronic paper) can be cited asrepresentative examples as the display device.

In the case of using a liquid crystal display device, a liquid crystalmaterial is filled between a pixel electrode and an optical filter. Apixel electrode may be provided on the optical filter. When a pixelelectrode is formed only on a side of the liquid crystal material, theliquid crystal display device is the one that can perform IPS modedisplay. When two pixel electrodes are provided sandwiching the liquidcrystal material, the liquid crystal display device is the one that canperform TN (twisted nematic) mode display, STN (super twisted nematic)mode display, and VA (vertical alignment) mode display.

In the case of using a light emitting display device, a light emittingelement includes a first electrode, a second electrode, and a layercontaining a luminescent substance that is provided between theelectrodes, wherein the first electrode is provided on the thirdsubstrate, and the second electrode is provided on a substrate (i.e.,the second substrate or the fourth substrate) that is opposite of thethird substrate. The light emitting element having such a structurecarries out a passive matrix driving display. Alternatively, in the casewhere a light emitting element includes a first pixel electrode, a layercontaining a luminescent substance, and a second pixel electrode thatare provided on the third substrate, the light emitting element havingsuch a structure carries out an active matrix driving display.

The optical filter is a color filter, a color conversion filter, or ahologram color filter.

The second substrate is formed of a plastic substrate. In this case, theoptical film including the second substrate and the optical filter is afilm having a color filter, a color conversion filter, or a hologramcolor filter.

An optical film can be used as the second substrate. As for the opticalfilm, a polarizing plate, an elliptical polarizing plate or a circularpolarizing plate composed of a retardation plate and a polarizingpalate, an antireflection film, a viewing angle improvement film, aprotective film, a luminance improvement film, a prism sheet, and thelike can be employed. The optical film including the optical filter andthe fourth substrate exhibits multiple optical properties.

The present invention further includes the following aspects.

According to an aspect of the invention, there is provided a method ofmanufacturing a display device that includes: a first step ofsequentially laminating a first metal film, a first oxide film, and anoptical filter on a first substrate, attaching a first support medium toa surface of the optical filter by using a first peelable adhesive agentsuch that the first support medium faces the first substrate through theoptical filter, and separating the first metal film from the first oxidefilm by a physical means; a second step of forming a layer including apixel on a second substrate; and a third step of attaching the firstoxide film to a surface of the layer including the pixel of the secondsubstrate by using a first adhesive material after the first and secondsteps, and removing the first peelable adhesive agent and the firstsupport medium.

After the third step, the third substrate may be attached to the surfaceof the optical filter by using a second adhesive material.

In this case, the first and second substrates are any of a quartzsubstrate, a ceramic substrate, a silicon substrate, a metal substrate,and a stainless substrate, while the third substrate is any one ofplastic, a polarizing plate, a polarizing plate (an ellipticalpolarizing plate or a circular polarizing plate) having a retardationplate, an antireflection film, a viewing angle improvement film, aprotective film, a luminance improvement film, a prism sheet, and thelike.

In the second step or the third step, the surface of the secondsubstrate can be attached with plastic, a polarizing plate, a polarizingplate (an elliptical polarizing plate or a circular polarizing plate)having a retardation plate, an antireflection film, a viewing angleimprovement film, a protective film, a luminance improvement film, aprism sheet, and the like.

Further, according to another aspect of the invention, there is provideda method of manufacturing a display device that includes: a first stepof sequentially laminating a first metal film, a first oxide film, andan optical filter on a first substrate, attaching a second substrate toa surface of the optical filter by using a first adhesive material suchthat the second substrate faces the first substrate through the opticalfilter, attaching a first support medium to a surface of the secondsubstrate by using a first peelable adhesive agent, and separating thefirst metal film from the first oxide film by a physical means so as toform an optical film; a second step of forming a layer including a pixelon a third substrate; and a third step of attaching the first oxide filmto a surface of the layer including the pixel of the third substrateafter the first and second steps, and removing the first peelableadhesive agent and the first support medium.

Further, according to another aspect of the invention, there is provideda method of manufacturing a display device that includes: a first stepof sequentially laminating a first metal film, a first oxide film, andan optical filter on a first substrate, attaching a first support mediumto a surface of the optical filter by using a first peelable adhesiveagent such that the first, support medium faces the first substratethrough the optical filter, separating the first metal film from thefirst oxide film by a physical means, attaching a second substrate to asurface of the first oxide film by using a first adhesive material, andremoving the first support medium and the first peelable adhesive agentso as to form an optical film; a second step of forming a layerincluding a pixel on a third substrate; and a third step of attachingthe optical filter to a surface of the layer including the pixel of thethird substrate by using a second adhesive material after the first andsecond steps.

The first and third substrates are any of a quartz substrate, a ceramicsubstrate, a silicon substrate, a metal substrate, and a stainlesssubstrate, while the second substrate is any one of plastic, apolarizing plate, a polarizing plate (an elliptical polarizing plate ora circular polarizing plate) having a retardation plate, anantireflection film, a viewing angle improvement film, a protectivefilm, a luminance improvement film, a prism sheet, and the like.

After the second and third steps, the surface of the third substrate canbe attached with plastic, a polarizing plate, a polarizing plate (anelliptical polarizing plate or a circular polarizing plate) having aretardation plate, an antireflection film, a viewing angle improvementfilm, a protective film, a luminance improvement film, a prism sheet,and the like.

Further, according to another aspect of the invention, there is provideda method of manufacturing a display device that includes: a first stepof sequentially laminating a first metal film, a first oxide film, andan optical filter on a first substrate, attaching a first support mediumto a surface of the optical filter by using a first peelable adhesiveagent such that the first support medium faces the first substratethrough the optical filter, and separating the first metal film from thefirst oxide film by a physical means; and a second step of sequentiallylaminating a second metal film and a second oxide film on a secondsubstrate, and forming a pixel electrode on the second oxide film; and athird step of attaching the first oxide film to a surface of the layerincluding the pixel of the second substrate by using a first adhesivematerial after the first and second steps, separating the second metalfilm from the second oxide film by using a physical means, attaching athird substrate to a surface of the second oxide film by using a secondadhesive material, and removing the first peelable adhesive agent andthe first support medium.

After the third step, a fourth substrate may be attached to the surfaceof the optical filter by using a third adhesive material.

In this case, the first and second substrates are any of a quartzsubstrate, a ceramic substrate, a silicon substrate, a metal substrate,and a stainless substrate, while the third and fourth substrates are anyof plastics, a polarizing plate, a polarizing plate (an ellipticalpolarizing plate or a circular polarizing plate) having a retardationplate, an antireflection film, a viewing angle improvement film, aprotective film, a luminance improvement film, a prism sheet, and thelike.

Further, according to another aspect of the invention, there is provideda method of manufacturing a display device that includes: a first stepof sequentially laminating a first metal film, a first oxide film, andan optical filter on a first substrate, attaching a second substrate toa surface of the optical filter by using a first adhesive material suchthat the second substrate faces the first substrate through the opticalfilter, attaching a first support medium to a surface of the secondsubstrate by using a first peelable adhesive agent, and separating thefirst metal film from the first oxide film by a physical means so as toform an optical film; a second step of sequentially laminating a secondmetal film and a second oxide film on a third substrate, and forming alayer including a pixel on the second oxide film; and a third step ofattaching the first oxide film to a surface of the layer including thepixel of the third substrate by using a second adhesive material afterthe first and second steps, separating the second metal film from thesecond oxide film by a physical means, attaching a fourth substrate to asurface of the second oxide film by using a third adhesive material, andremoving the first peelable adhesive agent and the first support medium.

Further, according to another aspect of the invention, there is provideda method of manufacturing a display device that includes: a first stepof sequentially laminating a first metal film, a first oxide film, andan optical filter on a first substrate, attaching a first support mediumto a surface of the optical filter by using a first peelable adhesiveagent such that the first support medium faces the first substratethrough the optical filter, and separating the first metal film from thefirst oxide film by a physical means; a second step of attaching asecond substrate to a surface of the first oxide film by using a firstadhesive material, and removing the first support medium and the firstpeelable adhesive agent so as to form an optical film; a third step ofsequentially laminating a second metal film and a second oxide film on athird substrate, and forming a layer including a pixel on the secondoxide film; and a fourth step of attaching the optical filter to asurface of the layer including the pixel by using a second adhesivematerial after first to third steps, separating the second metal filmfrom the second oxide film by a physical means, and attaching a fourthsubstrate to a surface of the second oxide film by using a thirdadhesive material.

A first metal oxide film may be formed between the first metal film andthe first oxide film simultaneously with forming the first metal filmand the first oxide film. Also, a second metal oxide film may be formedbetween the second metal film and the second oxide film simultaneouslywith forming the second metal film and the second oxide film.

The first oxide film may be formed after oxidizing the surface of thefirst metal film to form a first metal oxide film. Similarly, the secondoxide film may be formed after oxidizing the surface of the second metalfilm to form a second metal oxide film.

Further, a semiconductor element is electrically connected to the pixelelectrode. As for the semiconductor element, a TFT, an organicsemiconductor transistor, a diode, an MIM element, and the like areused.

Preferably, the first substrate is a heat-resistant substrate.Typically, a glass substrate, a quartz substrate, a ceramic substrate, asilicon substrate, a metal substrate, and a stainless substrate can beused as the first substrate.

The first and second metal films may be formed of an element selectedfrom titanium (Ti), aluminum (Al), tantalum (Ta), tungsten (W),molybdenum (Mo), copper (Cu), chromium (Cr), neodymium (Nd), iron (Fe),nickel (Ni), cobalt (Co), ruthenium (Ru), rhodium (Rh), palladium (Pd),osmium (Os), iridium (Ir); a single layer formed of an alloy material ora compound material containing the above-mentioned elements as its mainconstituent; a lamination layer thereof; or nitrides thereof. Further,after forming a spacer on the surface of the layer including the pixel,it can be attached to the second or third substrate.

According to the invention, the display device indicates a device usinga display element, i.e., an image display device. Further, the displaydevice includes all of a module in which a liquid crystal element isattached with a connector, e.g., a flexible printed circuit (FPC), a TAB(tape automated bonding) tape, or a TCP (tape carrier package); a modulehaving a printed wiring board provided on an end of a TAB tape or a TCP;and a module in that a display element is directly mounted with an IC(integrated circuit) or a CPU by the COG (chip on glass) technique.

In accordance with the present invention, a display device having anoptical film that includes a plastic substrate can be formed. As aconsequence, a lightweight, thin display device having an excellentimpact resistance property can be formed. In addition, a display devicehaving a curved surface or a display device, which can be varied inshape, can be manufactured.

In a display device using an optical film according to the invention, alayer including a pixel and an optical film are individually formedthrough different steps, and they are attached to each other aftercompletion. By using such a structure, the yield of a display element ora semiconductor element and the yield of the optical film can becontrolled individually, thereby suppressing reduction in the yield ofthe entire display device.

Furthermore, the steps of manufacturing an active matrix substrate andthe steps of manufacturing an optical film can be run simultaneously,reducing the manufacturing lead time of the display device.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A to 1E are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 2A to 2F are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 3A to 3F are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 4A to 4E are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 5A to 5D are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 6A and 6B are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 7A and 7B are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 8A and 8B are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 9A to 9C are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 10A and 10B are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIGS. 11A and 11B are cross sectional views explaining steps ofmanufacturing a display device according to the present invention;

FIG. 12A is a top view and FIG. 12B is a cross sectional view showing adisplay panel manufactured according to the invention;

FIG. 13A is a top view and FIG. 13B is a cross sectional view showing adisplay panel manufactured according to the invention;

FIGS. 14A and 14B are diagrams showing structures of a light emittingelement;

FIGS. 15A to 15C are circuit diagrams of pixels for light emittingelements;

FIG. 16A is a top view and FIG. 16B is a cross sectional view showing adisplay panel manufactured according to the invention;

FIG. 17A is a top view and FIG. 17B is a cross sectional view showing adisplay panel manufactured according to the invention;

FIG. 18 is a diagram explaining a structure of an electronic appliance;

FIG. 19 is a diagram explaining an example of an electronic appliance;and

FIGS. 20A and 20B are diagrams explaining an example of an electronicappliance.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment Mode 1

A method of manufacturing a display device having an optical film thatis formed using a plastic substrate will be described in the presentembodiment mode with reference to FIGS. 1A to 1E.

As shown in FIG. 1A, a first metal film 102 is formed on a firstsubstrate 101. As the first substrate, a heat-resistant material, i.e.,a material that can withstand a heat treatment in subsequent steps ofmanufacturing an optical filter and separating, typically, a glasssubstrate, a quartz substrate, a ceramic substrate, a silicon substrate,a metal substrate, or a stainless substrate can be used.

The first metal film 102 may be formed of an element selected fromtitanium (Ti), aluminum (Al), tantalum (Ta), tungsten (W), molybdenum(Mo), copper (Cu), chromium (Cr), neodymium (Nd), iron (Fe), nickel(Ni), cobalt (Co), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium(Os), iridium (Ir); a single layer formed of an alloy material or acompound Material containing the above-mentioned elements as its mainconstituent; or a lamination layer thereof. The first metal film mayalso be formed of nitrides of the above-mentioned elements or alamination layer thereof. Note that conditions of the subsequentseparation step are varied by adjusting a composition ratio of metal inalloy for the first metal film or a composition ratio of oxygen ornitrogen contained therein, properly. Therefore, the separation step canbe adapted to various kinds of processing. The first metal film 102 isformed by a known manufacturing method such as sputtering, CVD, andvapor deposition to have a thickness of 10 to 200 nm, preferably, 50 to75 nm.

A first oxide film 103 is next formed on the first metal film 102. Inthis case, a first metal oxide film is formed between the first metalfilm 102 and the first oxide film 103. When carrying out the separationstep in the subsequent step, separation will be caused inside the firstmetal oxide film, in an interface between the first metal oxide film andthe first oxide film, or in an interface between the first metal oxidefilm and the first metal film. As for the first oxide film 103, a layermay be formed of silicon oxide, silicon oxynitride, or metal oxide bysputtering or plasma CVD. It is desirable that the thickness of thefirst oxide film 103 be thicker than that of the first metal film 102,preferably, at least two times, or more preferably, at least four timesas thicker as the first metal film 102. The thickness of the first oxidefilm 103 is, herein, set to 200 to 800 nm, preferably, 200 to 300 nm.

An optical filter 104 is next formed on the first oxide film 103. Asrepresentative examples of the optical filter, a color filter, a colorconversion filter, a hologram color filter, and the like can be cited.

Subsequently, a second substrate 112 is pasted to a surface of theoptical filter 104 by using a first adhesive material 111. Various kindsof curing adhesive materials including a reactive curing adhesivematerial, a thermal curing adhesive material, a light curing adhesivematerial such as an ultraviolet curing adhesive material, and ananaerobic curing adhesive material can be used as the adhesive material.As representative examples of these materials, organic resins such as anepoxy resin, an acrylic resin, and a silicon resin can be cited.

A plastic substrate (a film made from a high molecular weight materialor a resin) is used as the second substrate 112. As representativeexamples of the plastic substrate, plastic substrates such aspolycarbonate (PC); ARTON formed of norbomene resin with a polar radicalthat is manufactured by JSR Corporation; polyethylene terephthalate(PET); polyether sulfone (PES); polyethylene naphthalate (PEN); nylon;polyether ether ketone (PEEK); polysulfone (PSF); polyetherimide (PEI);polyarylate (PAR); polybutylene terephthalate (PBT); and polyimide canbe used. Besides, optical films such as a polarizing plate, a polarizingplate (an elliptical polarizing plate or a circular polarizing plate)having a retardation plate, an antireflection film, a viewing angleimprovement film, a protective film, a luminance improvement film, and aprism sheet can be used as the second substrate.

Subsequently, a first support medium 121 is attached to a surface of thesecond substrate 112 with a first peelable adhesive agent 122. At thismoment, when air bubbles intrude between the second substrate 112 andthe first peelable adhesive agent 122, the optical filter will be easilycracked in the subsequent separation step. In order to prevent cracking,the first support medium is attached thereto so as not to generate airbubbles therebetween. By using a tape mounter device and the like, thefirst support medium can be attached at short times without mixing airbubbles therebetween.

Preferably, a substrate having higher rigidity than those of the firstsubstrate 101 and the second substrate 112, typically, a quartzsubstrate, a metal substrate, or a ceramic substrate is used as thefirst support medium 121.

As for the first peelable adhesive agent 122, an adhesive material madefrom an organic resin can be used. Representatively, followings can beexemplified: various kinds of peelable adhesive materials including areactive peelable adhesive material, a thermal peelable adhesivematerial, a light peelable adhesive material such as an ultravioletpeelable adhesive material, and an anaerobic peelable adhesive material;and a member having adhesive layers made from the above peelableadhesive materials on both surfaces thereof (typically, a two-sidedtape, and a two-sided sheet).

In FIG. 1A, the first substrate 101 and the first metal film 102 formedthereon are referred to as a first separation body 123. Further, layersfrom the first oxide film 103 to the second substrate 112 (i.e., layerssandwiched between the first metal film 102 and the first peelableadhesive agent 122) are referred to as a first subject body 124.

It is preferable that a support medium be bonded to the first substrate101 by using a peelable adhesive agent so as to prevent breakage of eachsubstrate. By bonding the support medium thereto, the separation step,which will be carried out later, can be performed easily with a smallerforce. Preferably, a substrate having higher rigidity than that of thefirst substrate, typically, a quartz substrate, a metal substrate, and aceramic substrate are used as the support medium.

As shown in FIG. 1B, the first separation body 123 is next separatedfrom the first subject body 124 by a physical means. The physical forceindicates, for example, a relatively small force such as hand power, gaspressure applied through a nozzle, ultrasonic waves, and load using awedge-shaped member.

As a result, separation is caused inside the first metal film 102,inside the first metal oxide film, in an interface between the firstmetal oxide film and the first oxide film, or in an interface betweenthe first metal oxide film and the first metal film so that the firstseparation body 123 can be separated from the first subject body 124 bya relatively small force.

To separate the separation body easily, a pretreatment is preferablycarried out as a previous step prior to the separation step. Typically,a treatment for partly reducing the adhesiveness between the first metalfilm 102 and the first oxide film 103 is performed. The treatment forpartly reducing the adhesiveness therebetween is performed by partlyirradiating laser beam to the first metal film 102 along a rim of aregion to be separated, or performed by partly damaging inside or aninterface of the first metal film 102 by locally applying pressure alonga rim of a region to be separated from an external portion.Specifically, a hard needle such as a diamond pen may perpendicularly bepressed and moved while applying load thereto. A scriber device ispreferably used to move the hard needle while applying pressure withpress force of from 0.1 to 2 mm. Accordingly, it is important to form aportion where a separation phenomenon is easily caused, i.e., a triggerof the separation phenomenon, prior to performing the separation step.By performing the pretreatment of selectively (partly) reducing theadhesiveness in advance, poor separation can be prevented, therebyimproving the yield.

According to the above-mentioned steps, an optical film provided on theplastic substrate can be formed. The plastic substrate and the opticalfilter formed thereon (i.e., the first subject body 124) are, herein,referred to as an optical film.

In the optical film according to the present embodiment mode, an organicresin that is the adhesive material 111 is interposed between theoptical filer and the second substrate 112, while the first oxide film103 is provided on a surface of the optical filter, where is opposite toa surface contacting to the organic resin.

The second substrate 112 can be made from an optical film such as apolarizing plate, a retardation plate, and a light diffusing film. Aknown antireflection film can further be provided on a surface of thesecond substrate or the oxide film. By using the structure, an opticalfilm having plural optical properties can be formed.

As shown in FIG. 1C, a second metal film 132 and a second oxide film 133are sequentially formed on a third substrate 131: A substrate formed ofthe same material as the first substrate can be used as the thirdsubstrate. Also, the second metal film 132 can be formed using the samemanufacturing steps, material, and structure as the first metal film102. Similarly, the second oxide film 133 can be formed using the samemanufacturing steps, material, and structure as the first oxide film103.

A layer 134 including a pixel is formed on the second oxide film 133.The layer including the pixel represents a layer on which an element oran electrode functioning as a pixel, typically, a liquid crystalelement, a light emitting element, a pixel electrode, a micromirrorarray, an electron emitter, and the like are provided in a displaydevice. Besides, an element for driving the pixel, typically, a TFT, anorganic semiconductor transistor, a diode, an MIM element, and the likemay also be provided thereon.

The first subject body 124, i.e., the optical film that is formed inFIG. 1B is attached to the surface of the layer 134 including the pixel.Specifically, the first oxide film 103 of the first subject body 124 isattached to the surface of the layer 134 including the pixel by using asecond adhesive material (not shown). The same material as the firstadhesive material 111 can be used for the second adhesive material.

As shown in FIG. 1D, the second oxide film 133 is separated from thesecond metal film 132 by using a physical means in the same manner asthe step as shown in FIG. 1B. According to the step, the third substrate131 and the second metal film 132 are separated from the second oxidefilm 133.

As shown in FIG. 1E, a fourth substrate 141 is attached to a surface ofthe second oxide film 133 or the second metal oxide film with a thirdadhesive material 142. A plastic substrate can be employed for thefourth substrate 141 as well as the second substrate 112. The firstpeelable adhesive agent 122 and the first support medium 121 areseparated from the second substrate 112.

According to the above-mentioned steps, a display device including theoptical film formed with the plastic substrate can be fabricated. As aconsequence, a lightweight, thin display device having an excellentimpact resistance property can be formed. In addition, a display devicehaving a curved surface or a display device that can be varied in shapecan be manufactured.

Embodiment Mode 2

In the present embodiment mode, a method of manufacturing an opticalfilm, and a method of manufacturing a display device using the same willbe described with reference to FIGS. 2A to 2F. Note that the opticalfilm of the embodiment mode includes different structure of that ofEmbodiment Mode 1 with respect to bonding surfaces for the opticalfilter and the second substrate.

As shown in FIG. 2A, a first metal film 102 and a first oxide film 103are sequentially formed on a first substrate 101, and an optical filter104 is formed on the first oxide film 103 in the same manner asEmbodiment Mode 1. Note that a first metal oxide film is formed betweenthe first metal film and the first oxide film.

A first support medium 121 is attached to a surface of the opticalfilter 104 with a first peelable adhesive agent 122. The first substrate101 and the first metal film 102 formed thereon are, herein, referred toas a first separation body 123. Meanwhile, the first oxide film 103 andthe optical filter 104 (i.e. layers sandwiched between the first metalfilm 102 and the first peelable adhesive agent 122) are referred to as asubject body 224.

A support medium is preferably bonded to the first substrate 101 with apeelable adhesive agent so as to prevent breakage of each substrate. Bybonding the support medium thereto, the separation step, that will becarried out later, can be performed easily with a smaller force.Preferably, a substrate having higher rigidity than that of the firstsubstrate, typically, a quartz substrate, a metal substrate, and aceramic substrate are used as the support medium.

In the case where the surface of the optical filter 104 is uneven, aplanarizing layer may be provided on the surface of the optical filter.By providing the planarizing layer, air bubbles can be prevented fromintruding between the optical filter 104 and the first peelable adhesiveagent 122, thereby improving the reliability of the separation step. Theplanarizing layer can be made from a material that can be formed byapplication such as an applied insulating film and an organic resin.When the planarizing layer is formed using a peelable material,typically, an adhesive material, the layer can be removed later.

As depicted in FIG. 2B, the first separation body 123 is separated fromthe first subject body 224 using a physical means. To separate theseparation body easily, the pretreatment as described in Embodiment Mode1 is preferably carried out as a previous step before the separationstep. By performing the pretreatment, separation is caused inside thefirst metal oxide film, in an interface between the first metal oxidefilm and the first oxide film, or in an interface between the firstmetal oxide film and the first metal film so that the first separationbody 123 can be separated from the first subject body 224 with arelatively small force. The physical means as explained in EmbodimentMode 1 may be employed properly.

As shown in FIG. 2C, the first oxide film 103 and a second substrate 112are attached to each other by using the first adhesive material 111. Asecond support medium 221 is next attached to a surface of the secondsubstrate using a second peelable adhesive agent 222. Afterwards, thefirst peelable adhesive agent 122 and the first support medium 121 areremoved from the optical filter 104. The same materials and structuresas those of the first peelable adhesive agent 122 and the first supportmedium 121 can be used for the second peelable adhesive agent 222 andthe second support medium 221, respectively.

In accordance with the above-described steps, an optical film can beformed. That is, the optical filter 104 can be provided on the secondsubstrate 112.

In the embodiment, an organic resin that is the adhesive material 111and the first oxide film 103 are interposed between the second substrate112 and the optical filter 104.

Alternatively, the separation step as shown in FIGS. 2A and 2B may beperformed after forming a conductive film as a pixel electrode on asurface of the optical filter 104. According to the step, an opticalfilm having the pixel electrode can be formed.

As the second substrate 112, it is possible to use a polarizing plate; apolarizing plate (including an elliptical polarizing plate and acircular polarizing plate) with a retardation plate; an antireflectionfilm; a viewing angle improvement film; a protective film; a luminanceimprovement film; a prism sheet; and the like. Also, a knownantireflection film can be formed on the surface of the secondsubstrate. By utilizing the structure, an optical film having pluraloptical properties can be formed.

Next, as shown in FIG. 2D, a second metal film 132 and a second oxidefilm 133 are sequentially laminated on a third substrate 131 in the samemanner as Embodiment Mode 1.

A layer 134 including a pixel is formed on the second oxide film 133.

Subsequently, the optical film manufactured in FIG. 2C, i.e., theoptical filter provided on the second substrate is attached to a surfaceof the layer 134 including the pixel. The optical filter 104 of theoptical film is attached to the surface of the layer 134 including thepixel with a second adhesive material (not shown). The same material asthe first adhesive material can be used for the second adhesivematerial.

As shown in FIG. 2E, the second oxide film 133 is separated from thesecond metal film 132 by using a physical means in the same manner asthe step shown in FIG. 2B. In accordance with the step, the thirdsubstrate 131 and the second metal film 132 are separated from the layer134 including the pixel.

As shown in FIG. 2F, a fourth substrate 141 is attached to the surfaceof the second oxide film 133 by using a third adhesive material 142. Aplastic substrate can be used for the fourth substrate 141 as well asthe second substrate 112. The second peelable adhesive agent 222 and thesecond support medium 221 are next separated from the second substrate112.

According to the above-described steps, a display device including aplastic substrate can be manufactured. That is, a display device usingthe optical film formed on the plastic substrate as an opposingsubstrate can be fabricated. As a consequence, a lightweight, thindisplay device having an excellent impact resistance property can beformed. In addition, a display device having a curved surface or adisplay device that can be varied in shape can be manufactured.

Embodiment Mode 3

The present embodiment mode explains the following steps with referenceto FIGS. 3A to 3F: an optical film is transferred to a surface of alayer including a pixel, and a plastic substrate is attached thereon tofabricate an opposing substrate of a display device.

As shown in FIG. 3A, a first metal film 102 and a first oxide film 103are sequentially formed on a first substrate 101, and an optical filter104 is formed on the first oxide film 103 in the same manner asEmbodiment Mode 1. Note that a first metal oxide film is formed betweenthe first metal film and the first oxide film.

The first support medium 121 is attached to a surface of the opticalfilter 104 using a first peelable adhesive agent 122. The firstsubstrate 101 and the first metal film 102 formed thereon are referredto as a first separation body 123. Meanwhile, the first oxide film 103and the optical filter 104 (i.e., layers sandwiched between the firstmetal film 102 and the first peelable adhesive agent 122) are referredto as a first subject body 224.

Preferably, a support medium is pasted to the first substrate 101 with apeelable adhesive agent in order to prevent breakage of each substrate.When the surface of the optical filter 104 is uneven, a planarizinglayer may be provided thereon.

As shown in FIG. 3B, the first separation body 123 is separated from thefirst subject body 224 by using a physical means. To separate theseparation body easily, the pretreatment as described in Embodiment Mode1 is preferably carried out as a previous step prior to the separationstep. By conducting the pretreatment, separation can be easily causedinside the first metal oxide film, in an interface between the firstmetal oxide film and the first oxide film, or in an interface betweenthe first metal oxide film and the first metal film so that the firstseparation body 123 can be separated from the first subject body 224 bya relatively small force.

As depicted in FIG. 3C, a second metal film 132 and a second oxide film133 are sequentially formed on a second substrate 331 in the same manneras Embodiment Mode 1. The same substrate as the third substrate 131employed in Embodiment Mode 1 can be used for the second substrate 331.

A layer 134 including a pixel is next formed on the oxide film 133.

The subject body 224 fabricated in FIG. 3B, i.e., the optical filter isattached to a surface of the layer 134 including the pixel.Specifically, the first oxide film 103 of the subject body 224 isattached to the surface of the layer 134 including the pixel by using afirst adhesive material (not shown). The same material as the firstadhesive material 111 shown in Embodiment Mode 1 can be used for thefirst adhesive material.

As shown in FIG. 3D, the second oxide film 133 is separated from thesecond metal film 132 by a physical means in the same manner as the stepshown in FIG. 3B. According to the step, the second substrate 331 andthe second metal film 132 are separated from the layer 134 including thepixel.

As shown in FIG. 3E, a third substrate 341 is fixed to the surface ofthe first oxide film 133 using a second adhesive material 342. The thirdsubstrate 341 and the second adhesive material 342 can use the samematerials as the fourth substrate 141 and the first adhesive material111 of Embodiment Mode 1, respectively. The first peelable adhesiveagent 122 and the first support medium 121 are next separated from theoptical filter 104.

A fourth substrate 343 is fixed to the surface of the optical filter 104using a third adhesive material 344. The fourth substrate 343 and thethird adhesive material 344 use the same materials of the fourthsubstrate 141 and the first adhesive material 111 of Embodiment Mode 1,respectively.

As shown in Embodiment Mode 2, a color filter may be attached to thesurface of the layer including the pixel, as substitute for EmbodimentMode 1. When a protective film is formed on the surface of the opticalfilter 104, a display device can be manufactured without providing thefourth substrate thereon.

According to the above-mentioned steps, a display device including theplastic substrate can be fabricated. That is, the present embodimentmode makes it possible to fabricate a display device using the opticalfilm formed on the plastic substrate as the opposing substrate. As aconsequence, a lightweight, thin display device having an excellentimpact resistance property can be formed. In addition, a display devicehaving a curved surface or a display device that can be varied in shapecan be manufactured.

Embodiment Mode 4

In the present embodiment mode, a method of manufacturing a displaydevice having optical films, which are formed according to any one ofEmbodiment Mode 1 to Embodiment Mode 3, on both surfaces thereof will bedescribed referring to FIGS. 4A to 4E. Note that the present embodimentmode uses Embodiment Mode 1 by way of example.

As shown in FIG. 4A, a first metal film 102 and a first oxide film 103are sequentially formed on a first substrate 101, and an optical filter104 is formed on the first oxide film 103 in the same manner asEmbodiment Mode 1. Note that a first metal oxide film is formed betweenthe first metal film 102 and the first oxide film 103.

A second substrate 112 is attached to a surface of the optical filter104 using a first adhesive material 111, and a first support medium 121is attached to a surface of the second substrate by using a firstpeelable adhesive agent 122. The first substrate 101 and the first metalfilm 102 formed thereon are referred to as a first separation body 123.Meanwhile, the first oxide film 103 and the optical filter 104 (i.e.,layers sandwiched between the first metal film 102 and the firstpeelable adhesive agent 122) are referred to as a first subject body124.

Subsequently, as shown in FIG. 4B, the separation body 123 is separatedfrom the subject body 124 by a physical means as well as EmbodimentMode 1. To separate the separation body easily, a pretreatment ispreferably carried out as a previous step prior to the separation step.By conducting the pretreatment, separation can be easily caused insidethe first metal oxide film, in an interface between the first metaloxide film and the first oxide film, or in an interface between thefirst metal oxide film and the first metal film so that the firstseparation body 123 can be separated from the first subject body 124 bya relatively small force.

In accordance with the above-mentioned steps, the optical film can thusbe formed. That is, the optical filter 104 can be provided on the secondsubstrate 112.

As depicted in FIG. 4C, a second metal film 132 and a second oxide film133 are sequentially formed on a third substrate 131 in the same manneras Embodiment Mode 1.

A layer 134 including a pixel is formed on the second oxide film 133.[0103] The subject body 124 that is fabricated in FIG. 4B, i.e., theoptical film is attached to a surface of the layer 134 including thepixel. Specifically, the first oxide film 103 of the subject body 124 isattached to the surface of the layer 134 including the pixel by using asecond adhesive material (not shown). The same material as the firstadhesive material 111 can be used for the second adhesive material.

As shown in FIG. 4D, the second oxide film 133 is separated from thesecond metal film 132 by a physical means in the same manner as thesteps shown in FIG. 4B. According to the step, the third substrate 131and the second metal film 132 are separated from the layer 134 includingthe pixel.

A second subject body 224, which is fabricated according to the stepsshown in FIGS. 4A and 4B, is attached to the surface of the second oxidefilm 133 by using a fourth adhesive material 425. The second subjectbody 424 is composed by laminating a third oxide film 403, a secondoptical filter 404, a third adhesive material 411, a fourth substrate412, a second peelable adhesive agent 421, and a second support medium422 as well as the first subject body 124. The materials for therespective layers of the first subject body 124 can be used asrespective layers of the second subject body. Thereafter, the secondpeelable adhesive agent 421 and the second support medium 422 areseparated from the fourth substrate 412. Further, the first peelableadhesive agent 122 and the first support medium 121 are separated fromthe second substrate 112.

Although the display device is fabricated by using the optical filmsmanufactured according to Embodiment Mode 1, the present embodiment modeis not particularly limited thereto. The display device can bemanufactured by properly transferring the optical film fabricatedaccording to Embodiment Mode 2 or Embodiment Mode 3 as an opposingsubstrate.

According to the invention, a display device including the plasticsubstrate can be fabricated. As a consequence, a lightweight, thindisplay device having an excellent impact resistance property can beformed. In addition, a display device having a curved surface or adisplay device that can be varied in shape can be manufactured.

Further, the display device having the optical films on both surfacesthereof can be manufactured in accordance with the present embodimentmode, which allows the display device to display images on both surfacesthereof.

Embodiment Mode 5

In the present embodiment mode, a method of manufacturing a displaydevice by using different kinds of substrates will be described withreference to FIGS. 5A to 5D.

As shown in FIG. 5A, a first metal film 102 and a first oxide film 103are sequentially formed on a first substrate 101, and an optical filter104 is formed thereon in the same manner as Embodiment Mode 1. Note thata first metal oxide film is formed between the first metal film 102 andthe first oxide film 103.

A second substrate 112 is attached to the surface of the optical filter104 using a first adhesive material 111, and a first support medium 121is attached thereto by using a first peelable adhesive agent 122. Thefirst substrate 101 and the first metal film 102 formed thereon are,herein, referred to as a first separation body 123. Meanwhile, the firstoxide film 103, the optical filter 104, the first adhesive material 111,and the second substrate 112 (i.e., layers sandwiched between the metalfilm 102 and the first peelable adhesive agent 122) are referred to as afirst subject body 124.

Subsequently, as shown in FIG. 5B, the separation body 123 is separatedfrom the subject body 124 by a physical means as well as EmbodimentMode 1. To separate the separation body easily, the pretreatment asdescribed in Embodiment Mode 1 is preferably carried out as a previousstep prior to the separation step. By conducting the pretreatment,separation can be easily caused inside the first metal oxide film, in aninterface between the first metal oxide film and the first oxide film,or in an interface between the first metal oxide film and the firstmetal film so that the first separation body 123 can be separated fromthe first subject body 124 by a relatively small force.

In accordance with the above-mentioned steps, the optical film can thusbe formed. That is, the optical filter 104 can be provided on the secondsubstrate 112.

A layer 134 including a pixel is next formed on a third substrate 131 asdepicted in FIG. 5C. The third substrate 131 of Embodiment Mode 1 can beused for the third substrate 131 of the present embodiment mode.Preferably, a polished substrate is used as the third substrate suchthat a display device formed later can be fabricated thinly. Inaddition, a fourth substrate may be attached to the surface of the thirdsubstrate. In this case, when a plastic substrate is used for the fourthsubstrate as well as the second substrate 112 of Embodiment Mode 1, theimpact resistance properties can be further improved.

The third substrate as shown in Embodiment Mode 1 is a heat-resistantsubstrate, and typically, a glass substrate, a quartz substrate, aceramic substrate, a silicon substrate, a metal substrate, and the likecan be used for the third substrate.

Subsequently, the first subject body 124 manufactured in FIG. 5B, i.e.,the optical film is attached to a surface of the layer 134 including thepixel. Concretely, the first oxide film 103 of the first subject body124 is attached to the surface of the layer 134 including the pixel byusing a second adhesive material (not shown). The same material as thefirst adhesive material 111 can be used for the second adhesivematerial.

As shown in FIG. 5D, the first peelable adhesive agent 122 and the firstsupport medium 121 are separated.

According to the above-mentioned steps, the display device havingmultiple kinds of substrates can be manufactured.

Although the optical film is, herein, formed according to EmbodimentMode 1, it can be fabricated in accordance with Embodiment Mode 2 orEmbodiment Mode 3 in place of Embodiment Mode 1.

According to the invention, a display device including the optical filmthat is formed using the plastic substrate can be fabricated.Consequently, a lightweight, thin display device having an excellentimpact resistance property can be formed.

Since the display device is manufactured using plural kinds ofsubstrates in the present embodiment mode, it is possible to select asuitable substrate depending on process conditions. In addition, sincethe plastic substrate is used, a display device having superior impactresistance property can be manufactured.

Embodiment Mode 6

With respect to any one of Embodiment Mode 1 through Embodiment Mode 3,a step of causing a separation between a separation body and a subjectbody more easily will be described in the present embodiment mode. Theembodiment mode uses Embodiment Mode 1 for the sake of explanationreferring to FIGS. 1A to 1E. Note that the present embodiment mode canbe applicable to any one of Embodiment Mode 2 through Embodiment Mode 5,in place of Embodiment Mode 1.

After forming the first metal film 102 and the first oxide film 103 onthe first substrate 101, the substrate is heated. Thereafter, theoptical film 104 is formed thereon. By conducting the heat treatment,the first metal film 102 can be separated from the first oxide film 103easily with a smaller physical force. In this case, the heat treatmentcan be carried out in the temperature range that is withstood by thefirst substrate, typically, in the range of 100 to 600° C., preferably,in the range of 150 to 500° C.

As substitute for the heat treatment, laser beam may be irradiated fromthe side of the first substrate 101. Also, a combined treatment of theheat treatment and laser beam irradiation treatment may be performed.

A continuous wave solid-state laser or a pulsed solid-state laser can beused here. As the continuous wave solid-state laser or the pulsedsolid-state laser, one or more of the following various kinds of laserscan typically be used: a YAG laser; a YVO₄ laser; a YLF laser; a YAlO₃laser; a glass laser; a ruby laser; an alexandrite laser; and aTi:sapphire laser. It is preferable to use the second harmonic wavethrough fourth harmonic wave of fundamental waves in the case of usingthe solid-state laser. Furthermore, as the other continuous wave lasersor pulsed lasers, there are an excimer laser; an Ar laser; and a Krlaser.

The laser beam can be irradiated to the first metal film 102 from a sideof the substrate, from a side of the first oxide film 103, or from bothsides of the substrate and the oxide film.

Further, a beam shape of the laser beam may be a circular shape, atriangular shape, a square shape, a polygonal shape, an ellipticalshape, or a linear shape. The size of the laser beam is not particularlylimited, and may be from several microns to several meters (that mayalso have either a doted shape or a planer shape). Furthermore, in theabove-mentioned oxidizing step, a portion to be irradiated with thelaser beam may be overlapped with a region where has been irradiatedwith the laser beam immediately before the portion, or may not beoverlapped therewith. In addition, it is preferable to use a laser beamhaving a wavelength of from 10 nm to 1 mm, more preferably, from 100 nmto 10 μm.

Consequently, the optical film manufactured in the embodiment mode canbe separated from the first substrate with a smaller physical force,thereby improving yield and reliability of a display device having theoptical film.

Embodiment Mode 7

With respect to any one of Embodiment Mode 1 through Embodiment Mode 5,a step of causing separation between a separation body and a subjectbody more easily will be described in the present embodiment mode. Notethat the present embodiment mode can be applicable to any one ofEmbodiment Mode 2 through Embodiment Mode 5, besides Embodiment Mode 1.

In the embodiment mode, a heat treatment is carried out after forming anoptical filter.

After forming a first metal film 102, a first oxide film 103, and anoptical filter 104 on a first substrate, the resultant first substrateis heated. Thereafter, a second substrate 112 is attached to the opticalfilter 104 using a first adhesive material 111 in Embodiment Mode 1.Meanwhile, a first support medium 121 is attached to the optical filter104 by using a first peelable adhesive agent 122 in Embodiment Mode 2.

By conducting the heat treatment, the first metal film 102 can beseparated from the first oxide film 103 by a smaller physical force. Atthis moment, the heat treatment can be carried out in the temperaturerange that is withstood by the first substrate or the optical filter,typically, in the range of 150 to 300° C., preferably, in the range of200 to 250° C.

As substitute for the heat treatment, laser beam may be irradiated fromthe side of the first substrate 101 as well as Embodiment Mode 6. Also,a combined treatment of the heat treatment and laser beam irradiationtreatment can be performed.

The optical film manufacture in the embodiment mode can be separatedfrom the first substrate with a smaller physical force, therebyimproving yield and reliability of a display device using the opticalfilm.

Embodiment Mode 8

The present embodiment mode will describe a method of forming an opticalfilm, which is different in the step of forming a metal oxide film ascompared with Embodiment Modes 1 through 7. The present embodiment modeuses Embodiment Mode 1 for the sake of explanation.

A metal film 102 is formed on a first substrate 101 in the same manneras Embodiment Mode 1. Subsequently, a metal oxide film is formed on asurface of the metal film 102. As a method of forming the metal oxidefilm thereon, followings can be cited: a thermal oxidation treatment; anoxygen plasma treatment; a treatment using a strong oxidizing solutionsuch as ozone water; and the like. By utilizing any one of the oxidizingmethods, the surface of the metal film 102 is oxidized to form the metaloxide film with a thickness of from 1 to 10 nm, preferably, from 2 to 5nm.

An oxide film 103 and an optical filter 104 are then formed on the metaloxide film in the same manner as Embodiment Mode 1. Thereafter, anoptical film can be achieved according to each embodiment mode.

Consequently, the metal oxide film that is a part of the separation bodycan be formed in the present embodiment mode, thereby forming an opticalfilm with high yield.

Embodiment Mode 9

The present embodiment mode will describe a structure of a lightemitting element that is applicable to any one of Embodiment Mode 1through Embodiment Mode 8 with reference to FIGS. 14A and 14B.

A light emitting element includes a pair of electrodes (an anode and acathode), and a layer containing a luminescent substance that issandwiched between the anode and the cathode. First electrodes,hereinafter, represent electrodes that are provided on the sides of thesecond substrates in Embodiment Modes 1, 2, 4, on the side of the fourthsubstrate in Embodiment Mode 3, and on the side of the third substratein Embodiment Mode 5, respectively, while second electrodes representelectrodes that are provided on substrates, which are opposite of theabove-mentioned substrates, in Embodiment Mode 1 through Embodiment Mode5, respectively.

The layer containing the luminescent substance includes at least a lightemitting layer, and is formed by laminating one or more of layers havingdifferent properties with respect to carries such as a hole injectinglayer, a hole transporting layer, a blocking layer, an electrontransporting layer, and an electron injecting layer, along with thelight emitting layer.

FIGS. 14A and 14B show examples of cross sectional structures for thelight emitting element.

In FIG. 14A, a layer 1403 containing a luminescent substance is composedby sequentially laminating a hole injecting layer 1404, a holetransporting layer 1405, a light emitting layer 1406, an electrontransporting layer 1407, and an electron injecting layer 1408 on a firstelectrode (anode) 1401. A second electrode (cathode) 1402 is provided onthe electron injecting layer 1408 to complete a light emitting element.In the case where a TFT for driving the light emitting element isprovided in the first electrode (anode), a p-channel TFT is used as theTFT.

Meanwhile, in FIG. 14B, a layer 1413 containing a luminescent substanceis composed by sequentially laminating an electron injecting layer 1418,an electron transporting layer 1417, a light emitting layer 1416, a holetransporting layer 1415, and a hole injecting layer 1414 on a firstelectrode (cathode) 1411. A second electrode (anode) 1412 is provided onthe hole injecting layer 1414 to complete a light emitting element. Whena TFT for driving the light emitting element is provided in the firstelectrode (cathode), an n-channel TFT is used as the TFT.

Note that this embodiment mode is not limited thereto. For example,various types of structures can be employed for the light emittingelement as follows: a structure of an anode/a hole injecting layer/alight emitting layer/an electron transporting layer/and a cathode, astructure of an anode/a hole injecting layer/a hole transporting layer/alight emitting layer/an electron transporting layer/an electroninjecting layer/and a cathode, a structure of an anode/a hole injectinglayer/a hole transporting layer/a light emitting layer/a hole blockinglayer/an electron transporting layer/and a cathode, a structure of ananode/a hole injecting layer/a hole transporting layer/a light emittinglayer/a hole blocking layer/an electron transporting layer/an electroninjecting layer/and a cathode, and the like. Note that a stripearrangement, a delta arrangement, a mosaic arrangement and the like canbe cited as the arrangement of a light-emitting region, that is to say,the arrangement of a pixel electrode. The first electrodes 1401 and 1411are made from conductive films with light-shielding properties. In FIG.14A, the first electrode 1401 serves as an anode, and hence, can beformed of a single layer of TiN, ZrN, Ti, W, Ni, Pt, Cr, Al, etc., alamination layer in combination with a titanium nitride film and analuminum-based film, or a three-layer structure of a titanium nitridefilm, an aluminum-based film, and another titanium nitride film.

In FIG. 14B, the first electrode 1401 serves as a cathode, andtherefore, can be formed of alkali metal such as Li and Cs, alkali earthmetal such as Mg, Ca, and Sr, an alloy containing the alkali metal andalkali earth metal (such as Mg:Ag and ALLO, and rare earth metal such asYb and Er. In the case of using an electron injecting layer made fromLiF, CsF, CaF₂, Li₂O, and the like, a normal thin conductive film suchas aluminum can be used as the first electrode.

The layers 1403 and 1413 containing the luminescent substances can beformed of known organic compounds such as a low molecular weightmaterial, a high molecular weight material, and a middle molecularweight material typified by oligomer, dendrimer, and the like. Also, alight emitting material (singlet compound) that emits light(fluorescence) by singlet excitation or a light emitting material(triplet compound) that emits light (phosphorescence) by tripletexcitation can be used.

Next, specific examples of materials for constituting the layers 1403and 1413 containing the luminescent substances are shown below.

In the case of an organic compound, a porphyrin compound is effective ashole injecting materials for forming the hole injecting layers 1404 and1414, and for example, phthalocyanine (hereinafter referred to asH₂—Pc), copper phthalocyanine (hereinafter referred to as Cu—Pc), andthe like can be used. As for the hole injecting materials, there is alsoa material in which a conductive polymer compound is subjected tochemical doping such as polyethylene dioxythiophene (hereinafterreferred to as PEDOT) doped with polystyrene sulfonate (hereinafterreferred to as PSS), polyaniline (hereinafter referred to as PAni), andpolyvinyl carbazole (hereinafter referred to as PVK). It is alsoeffective to use a thin film-made from an inorganic semiconductor suchas vanadium pentoxide or an ultra-thin film made from an inorganicinsulator such as aluminum oxide.

As hole transporting materials used for forming the hole transportinglayers 1405 and 1415, aromatic amine-based compounds (i.e., substanceshaving a benzene ring-nitrogen bond) are preferred. As the materialsthat are used widely, for example, there areN,N′-bis(3-methylphenyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine(abbreviation: TPD); a derivative thereof such as4,4′-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl (abbreviation: α-NPD);and the like. Further, star burst aromatic amine compounds such as4,4′,4″-tris(N, N-diphenyl-amino)-triphenylamine (abbreviation: TDATA),and 4,4′,4″-tris[N-(3-methylphenyl)-N-phenyl-amino]-triphenylamine(abbreviation: MTDATA) can also be cited.

Specific examples of the light emitting materials used for forming thelight emitting layers 1406 and 1416 include metal complexes such astris(8-quinolinolate)aluminum (abbreviation: Alq₃),tris(4-methyl-8-quinolinolate)aluminum (abbreviation: Almq₃),bis(10-hydroxybenzo[h]quinolinato) beryllium (abbreviation: BeBq₂),bis(2-methyl-8-quinolinolate)-(4-hydroxy-biphenylyl)-aluminum(abbreviation: BAlq), bis[2-(2-hydroxyphenyl)-benzoxazolate]zinc(abbreviation: Zn(BOX)₂), andbis[2-(2-hydroxyphenyl)-benzothiazolate]zinc (abbreviation: Zn(BTZ)₂).In addition, various kinds of fluorescent dyes are effective for thematerial of the light-emitting layers. It is also possible to usetriplet luminescent materials in which complexes include platinum oriridium as their central metal. For example, the followings are known asthe triplet luminescent materials: tris(2-phenylpyridine) iridium(abbreviation: Ir(ppy)₃); 2,3,7,8, 12, 13, 17,18-octaethyl-21H,23H-porphyrin-platinum (abbreviation: PtOEP); and thelike.

As electron transporting materials for forming the electron transportinglayers 1407 and 1417, the following metal complexes can be cited:tris(8-quinolinolate)aluminum (abbreviation: Alq₃);tris(4-methyl-8-quinolinolate)aluminum (abbreviation: Almq₃);bis(10-hydroxybenzo[h]quinolinato) beryllium (abbreviation: BeBq₂);bis(2-methyl-8-quinolinolate)-(4-hydroxy-biphenylyl)-aluminum(abbreviation: BAlq); bis[2-(2-hydroxyphenyl)-benzoxazolate]zinc(abbreviation: Zn(BOX)₂); bis[2-(2-hydroxyphenyl)-benzothiazolate]zinc(abbreviation: Zn(BTZ)₂); and the like. In addition to the metalcomplexes, the electron transporting layers use materials as follows:oxadiazole derivatives such as2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation:PBD), and 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene(abbreviation: OXD-7); triazole derivatives such as3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: TAZ) and3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: p-EtTAZ); imidazole derivatives such as2,2′,2″-(1,3,5-benzenetriyl)tris[1 phenyl-1H-benzimidazole](abbreviation: TPBI); and phenanthroline derivatives such asbathophenanthroline (abbreviation: BPhen) and bathocuproin(abbreviation: BCP).

As electron injecting materials used for forming the electron injectinglayers 1408 and 1418, the above-mentioned electron transportingmaterials can be used. Besides, an ultra-thin film made from aninsulator such as alkali metal halides (e.g., LiF and CsF), alkali earthhalides (e.g., CaF₂), and alkali metal oxides (e.g., Li₂O) is frequentlyused. In addition, alkali metal complexes such as lithiumacetylacetonate (abbreviation: Li(acac)) and 8-quinolinolate-lithium(abbreviation: Liq) can also be used effectively.

In the case of forming a light emitting display device according to thepresent embodiment mode, full color display can be performed by makingthe layer containing the luminescent substance to emit white light whileforming a color filter, additionally. Alternatively, full color displaycan be performed by making a layer containing a luminescent substance toemit blue light while providing a color conversion layer and the like,additionally.

Further, colored layers emitting red, green, and blue lights,respectively, are formed in the layers 1403 and 1413 containing theluminescent substances while using color filters so as to carry out fullcolor display. The light emitting display device having the structureexhibits high color purity of respective R, and B so that highdefinition display can be performed.

The second electrodes have polarities corresponding to the firstelectrodes 1401 and 1411, and are made from transparent conductivefilms.

In FIG. 14A, the second electrode 1402 serves as the cathode, andtherefore, can be formed by laminating an ultra thin film containingalkali metal such as Li and Cs and alkali earth metal such as Mg, Ca,and Sr, and a transparent conductive film (e.g., ITO, IZO, ZnO, and thelike). Or, the cathode may be formed by forming an electron transportinglayer formed by co-depositing an electron transporting material withalkali metal or alkali earth metal, and laminating a transparentconductive film (e.g., ITO, IZO, ZnO, etc.) thereon.

In FIG. 14B, the second electrode 1412 serves as the anode, andtherefore, is made from a transparent conductive film. In FIG. 14A, thefirst electrode serves as the anode, and therefore, is formed using atransparent conductive material such as indium-tin oxide (ITO), andindium-zinc oxide (IZO).

In FIG. 14A, when the first electrode 1411 (anode) is formed of atransparent conductive film, typically, a transparent conductivematerial such as indium-tin oxide (ITO), indium-zinc oxide (IZO), andindium-tin oxide containing silicon oxide (ITSO), light can be emittedboth toward the first electrode and the second electrode.

In FIG. 14B, light can be emitted both toward the first electrode andthe second electrode by using the structures as follows. The firstelectrode 1401 (cathode) is formed of a transparent conductive film,typically, a layer formed by laminating an ultra-thin film containing analkali metal (e.g., Li and Cs) together with an alkali earth metal(e.g., Mg, Ca, and Sr) and a transparent conductive film (ITO, IZO, ZnO,etc.). Or, an electron injecting layer is formed by co-depositing anelectron transporting material with an alkali metal or an alkali earthmetal, and a transparent conductive film (ITO, IZO, ZnO, etc.) islaminated thereon.

The light emitting elements shown in the embodiment mode emit lighttoward the second electrodes 1402 and 1412 (in the direction denoted byarrows in the drawing), respectively.

Embodiment 1

Steps of manufacturing a light emitting display device that correspondsto one embodiment of the display device according to the presentinvention will be explained with reference to FIGS. 6A and 6B, FIGS. 7Aand 7B, and FIGS. 8A and 8B. A color filter is used as a representativeexample of the optical filter in the present embodiment. Note that acolor conversion filter, a hologram color filter, and the like can beused in place of the color filter.

As shown in FIG. 6A, a separation layer is formed over a glass substrate(a first substrate 601). In the embodiment, AN100 is used as the glasssubstrate. A first metal film 602, e.g., a molybdenum film (with athickness of from 10 to 200 nm, preferably, from 50 to 75 nm) is formedon the glass substrate by sputtering. Subsequently, a first oxide film603, i.e., a silicon oxide film (with a thickness of from 10 to 400 nm,preferably, from 75 to 150 nm), is laminated thereon. Upon lamination, afirst metal oxide film (i.e., a molybdenum oxide film) is formed betweenthe first metal film 602 and the first oxide film 603. In the subsequentseparation step, separation will be caused inside the first molybdenumoxide film; in an interface between the first molybdenum oxide film andthe first silicon oxide film; or in an interface between the firstmolybdenum oxide film and the first molybdenum film.

As shown in FIG. 6B, a color filter 609 is next formed on the firstoxide film 603. As a method of manufacturing the color filter, thefollowing known methods can be employed: an etching method using acolored resin; a color resist method using color resist; a dyeingmethod; an electrodeposition method; a micelle electrolytic method; anelectrodeposition transfer method; a film diffusion method; an ink jetmethod (a droplet discharging method); a silver-salt coloring method;and the like.

In the present embodiment, a color filter is formed by the etchingmethod using a photosensitive resin in which pigments are dispersed.Firstly, a photosensitive acrylic resin in which a black pigment isdispersed is applied on the first oxide film 603 by application. Theacrylic resin is dried, baked temporarily, and subsequently, is exposedand developed. Thereafter, the acrylic resin is heated at a temperatureof 220° C. to be cured so that a black matrix 604 with a thickness offrom 0.5 to 1.5 μm is formed. Subsequently, a photosensitive acrylicresin in which a red pigment is dispersed, a photosensitive acrylicresin in which a green pigment is dispersed, and a photosensitiveacrylic resin in which a blue pigment is dispersed are applied over thesubstrate by application, respectively. Each photosensitive acrylicresin is subjected to the same steps of forming the black matrix so thata red colored layer 605 (hereinafter, referred to as a colored layer R),a green colored layer 606 (hereinafter, referred to as a coldred layerG), and a blue colored layer 607 (hereinafter, referred to as a coloredlayer B) are formed to have thicknesses of from 1.0 to 2.5 μm,respectively. Afterwards, an organic resin is applied over the resultantsubstrate to form a protective film (a planarizing layer) 608, therebyachieving a color filter 609.

In the present specification, the colored layer R represents a coloredlayer that transmits red light (having a peak wavelength in the vicinityof 650 nm) therethrough. The colored layer G represents a colored layerthat transmits green light (having a peak wavelength in the vicinity of550 nm) therethrough. The colored layer B represents a colored layerthat transmits blue light (having a peak wavelength in the vicinity of450 nm) therethrough.

A second substrate (a plastic substrate) 611 is attached to theprotective film (planarizing layer) 608 by using a first adhesivematerial 610. As for the first adhesive material 610, an epoxy resinthat is a light curing adhesive material is employed. A polycarbonatefilm is used as the second substrate 611. The oxide film formed on thesurface of the color filter, the color filter, the organic resin layer,and the plastic substrate are, herein, referred to as a substrate 614having a color filter.

Subsequently, a pretreatment is performed to carry out a separationtreatment easily, although not shown in the drawings. By using a scriberdevice, a hard needle is moved while applying the pressure with pressforce of from 0.1 mm to 2 mm so as to remove edges of the substrate inthe present embodiment. In this case, the first metal film 602 isseparated from the first oxide film 603. By reducing the adhesivenessselectively (partly) in advance in the pretreatment, poor separation canbe prevented, which results in the improved yield.

A first support medium 613 is attached to a surface of the secondsubstrate 611 by using a first peelable adhesive agent 612. A two-sidedtape is used as the first peelable adhesive agent 612, whereas a quartzsubstrate is used as the first support medium 613.

Next, as shown in FIG. 6B, a second support medium 622 is attached tothe first substrate 601 using a second peelable adhesive agent 621. Atwo-sided tape is used as the second peelable adhesive agent, whereas aquartz substrate is used as the second support medium as well as thefirst support medium.

As shown in FIG. 7A, the first substrate 601 is next separated from thesubstrate 614 having the color filter. Concretely, the first metal film602 is separated from the first oxide film 603 by a physical means. Theseparation step can be performed by a relatively small force (forexample, load with use of a member, hand power, gas pressure appliedfrom a nozzle, and ultrasonic waves, and the like). In the presentembodiment, a part of a member having a sharp end such as a wedge isinserted between the first metal film 602 and the first oxide film 603to separate the two layers. Thus, the substrate 614 having the colorfilter, which is formed on the first oxide film 603, can be separatedfrom the first substrate 601 and the first metal film 602. If theadhesive agent remains on the surface of the first oxide film 603, poorseparation might be caused. Therefore, the surface of the first oxidefilm 603 is preferably washed by O₂ plasma irradiation, ultraviolet rayirradiation, ozone cleaning, and the like.

According to the above steps, the color filter 609 is formed over theplastic substrate through the organic resin that is the first adhesivematerial 610. Note that, the first oxide film 603 is formed on thesurface of the color filter.

As shown in FIG. 7B, a second metal film 632 and a second oxide film 633are formed on a third substrate 631. The second metal film 632 and thesecond oxide film 633 can use the same materials and structures as thoseof the first metal film 602 and the first oxide film 603, respectively.In the present embodiment, a tungsten film is formed as the second metalfilm 632 by sputtering to have a thickness of from 10 to 200 nm,preferably, from 50 to 75 nm. A silicon oxide film is formed as thesecond oxide film 633 by sputtering to have a thickness of form 20 to800 nm, more preferably, 200 to 300 nm.

A light emitting element is next formed on the second oxide film 633 bya known method. A semiconductor element for driving the light emittingelement is, herein, provided. As for the semiconductor element, a TFT634 including a crystalline semiconductor film, which is formed by aknown method (e.g., solid phase growth, laser crystallization,crystallization using catalytic metal, and the like), is formed. The TFT634 is formed as follows: An amorphous silicon film is formed, and dopedwith a metal element such as nickel, iron, cobalt, platinum, titanium,palladium, copper, and iridium. The resultant amorphous semiconductorfilm is crystallized by heating to form a crystalline semiconductorfilm. The crystalline semiconductor film is patterned to form asemiconductor region having a predetermined shape so that a TFT havingthe semiconductor region as an active region is achieved. A structure ofthe TFT 634 is not particularly limited, and it may be either a top-gateTFT (typically, a planar TFT) or a bottom-gate TFT (typically, aninverted-stagger type TFT). Alternatively, an amorphous semiconductorfilm or a microcrystalline semiconductor film can be used rather thanthe crystalline semiconductor film. Also, an organic semiconductortransistor, a diode, an MIM element, and the like can be employed forthe semiconductor element, as substitute for the TFT.

A conductive film connecting to the TFT 634 is formed and etched to havea pixel size so that a first electrode 635 is formed. The firstelectrode 635 is formed using a transparent conductive film, and TiN is,herein, used by way of example. An insulator 640 (that is also referredto as a bank, a partition wall, a bather, an embankment, etc.) forcovering edges of the first electrode 635 (and a wiring) is formed by aknown method such as CVD, PVD, and application. The insulator 640 can bemade from inorganic materials (e.g., silicon oxide, silicon nitride,silicon oxynitride, etc.); photosensitive or nonphotosensitive organicmaterials (e.g., polyimide, acrylic, polyamide, polyimide amide, resist,benzocyclobutene, and the like); or a lamination thereof.

A layer 636 containing a luminescent substance is next formed by vapordeposition, application, ink jet, and the like. The layer 636 containingthe luminescent substance is formed of layers in combination with a holeinjecting layer, a hole transporting layer, an electron injecting layer,and an electron transporting layer together with a light emitting layer.Also, any known structure may be employed. The material for the lightemitting layer may be either organic materials or inorganic materials.In the case of using the organic materials, either high molecular weightmaterials or low molecular weight materials can be employed. Preferably,degasification is performed by vacuum heating prior to forming the layer636 containing the luminescent substance to improve the reliability.When using vapor deposition, for example, vapor deposition is carriedout in a film formation chamber, which is vacuum evacuated up to a levelof 5×10⁻³ Torr (0.665 Pa) or less, preferably, in the range of from 10⁻⁴to 10⁻⁶ Pa.

A second electrode 637 is then formed on the layer 636 containing theluminescent substance. The second electrode is made from a transparentconductive film, and an ultra thin film of an aluminum-lithium alloy is,for example, used in the embodiment.

The first electrode 635, the layer 636 containing the luminescentsubstance, and the second electrode 637 are collectively referred to asa light emitting element 638.

As shown in FIG. 7B, the substrate 614 having the color filter and thesecond electrode 637 are attached to each other using a sealing material639. The sealing material 639 uses an ultraviolet curing resin in theembodiment.

As shown in FIG. 8A, the second metal film 632 and the third substrate631 are removed from the second oxide film 633, as shown in FIG. 8A.Also, the first peelable adhesive agent 612 and the first support medium613 are removed from the third substrate 631.

As shown in FIG. 8B, a fourth substrate 645 is attached to the secondoxide film 633 with a third adhesive material 643.

Any one of Embodiment Modes 2 through 9 can be applied to the presentembodiment, in place of Embodiment Mode 1.

According to the embodiment, the color filter can be formed on theplastic substrate. In addition, when an optical film such as apolarizing plate, a retardation plate, and a light diffusing film isformed using the color filter, an optical film integrated with pluralproperties can be achieved.

Further, a display device having the optical film that includes theplastic substrate can be fabricated, and hence, a lightweight, thinlight emitting display device having an excellent impact resistanceproperty can be formed. Furthermore, a light emitting display devicehaving a curved surface or a light emitting display device that can bevaried in shape can be fabricated.

The light emitting display device manufacturing in the embodimentcomprises a structure as follows: the layer including the light emittingelement or the semiconductor element and the substrate having the colorfilter are formed separately through different steps, and they areattached to each other after completion. By utilizing the structure, theyield of the light emitting element or the semiconductor element and theyield of the optical film can be controlled individually, therebysuppressing reduction in the yield of the entire light emitting displaydevice.

In addition, the steps of manufacturing an active matrix substrate andthe steps of manufacturing the substrate having the color filter can berun simultaneously, thereby reducing the manufacturing lead lime for thedisplay device.

Embodiment 2

Steps of manufacturing a liquid crystal display device corresponding toone embodiment of the display device in the invention will be describedwith reference to FIGS. 9A to 9C, FIGS. 10A and 10B, and FIGS. 11A and11B. In the present embodiment, a color filter is used as arepresentative example of an optical filter. Note that a colorconversion filter, a hologram color filter, and the like can be used, inplace of the color filter.

As shown in FIG. 9A, a separation layer is formed on a glass substrate(a first substrate 901) in the same manner as Embodiment 1. AN100 is,herein, used as the glass substrate. A first metal film 902, e.g., amolybdenum film (with a thickness of from 10 to 200 nm, preferably, from50 to 75 nm) is formed on the glass substrate by sputtering, and a firstoxide film 903, e.g., a silicon oxide film (with a thickness of from 20to 800 nm, preferably, from 200 to 300 nm), is laminated thereon. Uponlaminating the first oxide film, a first metal oxide film (e.g., amolybdenum oxide film) is formed between the first metal film 902 andthe first silicon oxide film 903. In the subsequent separation step,separation will be caused inside the first molybdenum oxide film, in aninterface between the first molybdenum oxide film and the first siliconoxide film, or in an interface between the first molybdenum oxide filmand the first molybdenum film.

A color filter 909 is next formed on the first oxide film 903 as shownin FIG. 9B. In the embodiment, a black matrix 904 is formed to have athickness of 0.5 to 1.5 Inn by etching with use of a photosensitiveresin in which a pigment is dispersed. Subsequently, a red colored layer905 (hereinafter, referred to as a colored layer R), a green coloredlayer 906 (hereinafter, referred to as a colored layer G), and a bluecolored layer 907 (hereinafter, referred to as a colored layer B) areformed to have thicknesses of from 1.0 to 2.5 μm, respectively, byetching with use of photosensitive resins in which pigments ofrespective colors are dispersed. Thereafter, a protective film (aplanarizing layer) 908 is formed by applying an organic resin tocomplete the color filter 909.

A conductive film 911, which will serve as a pixel electrode(hereinafter referred to as a first pixel electrode), is formed on thecolor filter 909. The first pixel electrode is, herein, made from atransparent conductive film, typically, ITO.

A pretreatment for performing the separation step easily is carried outin the same manner as Embodiment 1, though not shown in the drawings.

A first support medium 913 is attached to a surface of the first pixelelectrode 911 using a first peelable adhesive agent 912. A two-sidedtape is, herein, used as the first peelable adhesive agent 912, while aquartz substrate is used as the first support medium 913.

As shown in FIG. 9B, a second support medium 922 is attached to thefirst substrate 901 by using a second peelable adhesive agent 921. Atwo-sides tape is used as the second peelable adhesive agent, while aquartz substrate is used as the second support medium as well as thefirst support medium.

As shown in FIG. 9C, the color filter 909 is separated from the firstsubstrate 901 in the same manner as Embodiment 1.

As shown in FIG. 10A, a second substrate 924 is attached to the surfaceof the first oxide film 903 using a first adhesive material 923. Thefirst adhesive material 923 uses a light curing adhesive material whilethe second substrate 924 uses a PEN substrate. According to the abovesteps, an optical film 914 including the color filter provided on thePEN substrate that is a plastic substrate can be formed.

Subsequently, a third support medium 926 is attached to a surface of thesecond substrate 924 with a third peelable adhesive agent 925. Atow-sided tape is used for the third peelable adhesive agent 925 whereasa quartz substrate is used for the third support medium 926 in theembodiment.

The first support medium 913 and the first peelable adhesive agent 912are separated from the first conductive film 911. If the adhesive agentremains on the surface of the first conductive film 911, poor separationmight be caused. Therefore, the surface thereof is preferably washed byO₂ plasma irradiation, ultraviolet ray irradiation, ozone cleaning, etc.so as to remove the residue. To remove moisture absorbed in the entireplastic substrate, vacuum heating may be carried out. In this case, thevacuum heating should be performed within an allowable temperature limitof plastic.

According to the above steps, the color filter 909 is formed over theplastic substrate (second substrate) through the organic resin, which isthe first adhesive material 923. The first oxide film 903 is interposedbetween the color filter and the organic resin. The color filter, theoxide film formed on the surface of the color filter, the organic resinlayer, and the plastic substrate are, herein, collectively referred toas a substrate 914 having the color filter.

As shown in FIG. 10B, a first alignment film 938 is formed on thesurface of the first pixel electrode 911. The alignment film uses analignment film that is formed by rubbing polyimide in the presentembodiment. Alternatively, an alignment film that is formed by obliquedeposition using silicon oxide or a photo-alignment film can be used.

A second metal filth 932 and a second oxide film 933 are next formed ona third substrate 931. As for the third metal film 932, a tungsten filmis formed by sputtering to have a thickness of 10 to 200 nm, preferably,50 to 75 nm. As for the second oxide film 933, a silicon oxide film isformed by sputtering to have a thickness of 150 to 200 nm.

A liquid crystal element is formed on the second oxide film 933 by aknown method. Also, a semiconductor element for driving the liquidcrystal element is provided in the embodiment. A TFT 934 using thecrystalline semiconductor film as described in Embodiment 1 is used asthe semiconductor element.

A conductive film made from ITO that serves as a second pixel electrode935 is connected to the TFT 934. A liquid crystal element 939 includesthe first pixel electrode 911, the second pixel electrode 935, and aliquid crystal material, which will be filled between the electrodeslater.

Next, a spacer 936 is formed on the layer on which the TFT 934 isprovided. The spacer is formed as follows: an organic resin is appliedand etched in a predetermined shape, typically, a pillar shape or acolumnar shape.

A second alignment film 940 is formed on the surfaces of the TFT 934,the second electrode 935, and the spacer 936. An alignment film formedby rubbing polyimide is used for the second alignment film as well asthe first alignment film.

Thereafter, the substrate 914 having the color filter and the layer withthe TFT and the second pixel electrode formed thereon are attached toeach other by using a first sealing material (not shown). Specifically,the first alignment film 938 and the second alignment film 940 areadhered to each other with the first sealing material.

As shown in FIG. 11A, the second metal film 932 and the third substrate931 are removed from the second oxide film 933. Subsequently, a fourthsubstrate 942 is attached to the second oxide film. Further, the thirdpeelable adhesive agent 925 and the third support medium 926 are removedfrom the second substrate 924.

As shown in FIG. 11B, a liquid crystal material 941 is filled betweenthe two pieces of substrates, i.e., between the first and secondalignment films 938, 940. By using a second sealing material (notshown), the two pieces of substrates are sealed completely.

According to the above steps, a liquid crystal display device 950 usingthe plastic substrate and the color filter formed on the plasticsubstrate as shown in FIG. 11B can be manufactured.

Although the present embodiment only shows a transmissive liquid crystaldisplay device, a reflective liquid crystal display device or asemiconductor transmissive liquid crystal display device can also beused.

The present embodiment is applicable to any one of Embodiment 1 andEmbodiment Modes 3 to 6, instead of Embodiment Mode 2.

According to the present invention, the color filter can be formed onthe plastic substrate. When an optical film such as a polarizing plate,a retardation plate, and a light diffusing film is formed using thecolor filter, an optical film integrated with plural properties can beachieved.

The liquid crystal display device manufactured according to theembodiment has a structure as follows: the layer including the liquidcrystal element or the semiconductor element and the substrate havingthe color filter can be manufactured separately through the differentsteps, and they are attached to each other after completion. Byutilizing the structure, the yield of the liquid crystal element or thesemiconductor element and the yield of the optical film can becontrolled individually, thereby suppressing reduction in the yield ofthe entire liquid crystal display device.

Further, the steps for manufacturing an active matrix substrate and thesteps for manufacturing the substrate having the color filter can be runsimultaneously, thereby reducing the manufacturing lead time of theliquid crystal display device.

Embodiment 3

In the present embodiment, an exterior appearance of a light emittingdisplay device panel corresponding to one embodiment of a display deviceaccording to the invention will be explained with reference to FIGS. 12Aand 12B. FIG. 12A shows a tow view of a panel in which a first substratewith a semiconductor element formed thereon and a second substratehaving a color filter are sealed with a first sealing material 1205 anda second sealing material 1206, while FIG. 12B shows a cross sectionalview taken along a line A-A′ of FIG. 12A.

In FIG. 12A, reference numeral 1201 denoted by a doted line represents asignal line driver circuit; 1202, a pixel portion; and 1203, a scanningline driver circuit. In the embodiment, the signal line driver circuit1201, the pixel portion 1202, and the scanning line driver circuit 1203are positioned within a region sealed with the first and second sealingmaterials. As the first sealing material, an epoxy resin containingfiller with high viscosity is preferably used. As the second sealingmaterial, an epoxy resin having low viscosity is preferably used.Further, it is desirable that the first and second sealing materials1205, 1206 be materials that do not transmit moisture and oxygen as muchas possible.

Reference numeral 1240 denotes a connection wiring for transmittingsignals inputted in the signal line driver circuit 1201 and the scanningline driver circuit 1203, and receives video signals and clock signalsvia a connection wiring 1208 from an FPC (flexible printed circuit)1209, which becomes an external input terminal.

Next, a cross sectional structure will be described referring to FIG.12B. The first substrate 1200 is provided with a driver circuit and apixel portion along with plural semiconductor elements typified by aTFT. A color filter 1223 is provided on a surface of a second substrate1204. The substrate 614 having the color filter (i.e., the secondsubstrate 1204 and the color filter 1223 provided thereon) that isformed according to Embodiment 1 can be used here. As for the drivercircuit, the signal line driver circuit 1201 and the pixel portion 1202are illustrated. A CMOS circuit formed in combination with an n-channelTFT 1221 and a p-channel 114T 1222 is provided as the signal line drivercircuit 1201.

Since the TFTs of the signal line driver circuit, the scanning linedriver circuit, and the pixel portion respectively are formed over thesame substrate in the present embodiment, the volume of the lightemitting display device can be reduced.

The pixel portion 1202 includes a plurality of pixels having a switchingTFT 1211, a driver TFT 1212, and a first electrode (anode) 1213 madefrom a conductive film with a light-shielding property, which iselectrically connected to a drain of the driver TFT 1212.

An interlayer insulating film 1220 of these TFTs 1211, 1212, 1221, and1222 may be formed of a material containing an inorganic material (suchas silicon oxide, silicon nitride, and silicon oxynitride) or an organicmaterial (such as polyimide, polyamide, polyimide amide,benzocyclobutene, and siloxane polymer) as its principal constituent.When the interlayer insulating film is formed of siloxane polymer, itbecomes to have a skeleton formed by the bond of silicon and oxygen andinclude hydrogen or/and alkyl group in a side chain.

An insulator (also referred to as a bank, a partition wall, a barrier,an embankment, etc.) 1214 is formed on each end of the first electrode(anode) 1213. To improve coverage of a film formed on the insulator1214, an upper edge portion or a lower edge portion of the insulator1214 is formed so as to have a curved surface having a radius ofcurvature. The insulator 1214 may be formed of a material containing aninorganic material (such as silicon oxide, silicon nitride, and siliconoxynitride) or an organic material (such as polyimide, polyamide,polyimide amide, benzocyclobutene, and siloxane polymer) as itsprincipal constituent. When the insulator is made from siloxane polymer,it becomes to have a skeleton formed by the bond of silicon and oxygenand include hydrogen or/and alkyl group in a side chain. Further, theinsulator 1214 may be covered with a protective film (a planarizinglayer) made from an aluminum nitride film, an aluminum nitride oxidefilm, a thin film containing carbon as its principal constituent, or asilicon nitride film.

An organic compound material is vapor deposited on the first electrode(anode) 1213 to form a layer 1215 containing a luminescent substance,selectively.

To remove gases contained in the substrate prior to performing the vapordeposition of the material for the layer containing the luminescentsubstance, a heat treatment at a temperature of 200 to 300° C. isdesirably carried out under a reduced pressure atmosphere or an inertatmosphere.

In order to make the layer 1215 containing the luminescent substanceemit white light, for example, white light emission can be achieved bysequentially laminating Alq₃, Alq₃ partially doped with Nile red, whichis a red light emitting pigment, Alq₃, p-EtTAZ, and TPD (aromaticdiamine) by using vapor deposition.

The layer 1215 containing the luminescent substance may be formed tohave a single layer. In this case, 1,3,4-oxadiazole derivative (PBD),which has electron transporting properties, may be dispersed inpolyvinyl carbazole (PVK), which has hole transporting properties. Inaddition, white light emission can also be obtained by dispersing 30 wt% of PBD as an electron transporting agent and dispersing a suitableamount of four kinds of pigments (TPB, coumarin 6, DCM1, and Nile red).In addition to the above-mentioned light emitting element that emitswhite light, a light emitting element that emits red light, green light,or blue light can be manufactured by properly selecting the materials ofthe layer 1215 containing the luminescent substance.

Note that triplet excited luminescent materials including metalcomplexes and the like may be used for the layer 1215 containing theluminescent substance, instead of the above-mentioned singlet excitedluminescent materials.

As a material for the second electrode (cathode) 1216, a transparentconductive film may be used.

Thus, a light emitting element 1217 including the first electrode(anode) 1213, the layer 1215 containing the luminescent substance, andthe second electrode (cathode) 1216 can be formed. The light emittingelement 1217 emits light toward the second substrate 1204. The lightemitting element 1217 is one example of light emitting elements thatemit white light. A full color display can be performed by transmittinglight emitted from the light emitting element 1217 through the colorfilter.

Alternatively, in the case where the light emitting element 1217 is oneof light emitting elements that emit monochromatic light of R, and Brespectively, a full color display can be performed by selectively usingthree light emitting elements with layers containing organic compounds,which emit respective colors of R, and B. In this case, a light emittingdisplay device with high color purity can be obtained by aligningrespective colored layers of red, green, and blue for the color filtersto the light emitting elements that emit respective colors.

A protective lamination layer 1218 is formed to encapsulate the lightemitting element 1217. The protective lamination layer is formed bylaminating a first inorganic insulating film, a stress relaxation film,and a second inorganic insulating film. The protective lamination layer1218 and the substrate 614 having the color filter (i.e., the secondsubstrate 1204 and the color filter 1223) are attached to each otherwith the first sealing material 1205 and the second sealing material1206. The surface of the second substrate 1204 is fixed with apolarizing plate 1225 using an adhesive material 1224. A surface of thepolarizing plate 1225 is provided with a retardation plate 1229 having½λ, or ¼λ, and an antireflection film 1226.

The connection wiring 1208 and the FPC 1209 are electrically connectedto one another with an anisotropic conductive film or an anisotropicconductive resin 1227.

As set forth above, one feature of the light emitting display deviceaccording to the present embodiment is that the layer having theelements and the color filter are formed separately through thedifferent steps, and they are attached to each other after completion.According to the structure, the yield of the layer having the elements,i.e., the TFTs and the liquid crystal element and the yield of the colorfilter can be controlled individually, thereby suppressing reduction inthe yield of the entire light emitting display device.

Further, the steps of manufacturing an active matrix substrate and thesteps of manufacturing the color filter can run simultaneously, reducingthe manufacturing lead time for the light emitting display device.

Further, since the plastic substrate is used, a lightweight lightemitting display device having an improved impact resistance propertycan be manufactured.

Embodiment 4

In the present embodiment, an exterior appearance of a light emittingdisplay device panel corresponding to one embodiment of a display deviceaccording to the invention will be explained with reference to FIGS. 13Aand 13B. FIG. 13A shows a tow view of a panel in which a first substratewith a semiconductor element formed thereon and a second substratehaving a color filter are attached to each other by using a firstsealing material 1205 and a second sealing material 1206. FIG. 13Bcorresponds to a cross sectional view taken along a line A-A′ of FIG.13A. In the embodiment, an example in which a signal line driver circuitusing an IC chip is mounted on the light emitting display device isshown.

In FIG. 13A, reference numeral 1230 represents a signal line drivercircuit; 1202, a pixel portion; and 1203, a scanning line drivercircuit. Further, reference numeral 1200 denotes the first substrate;reference numeral 1204 denotes the second substrate; and referencenumerals 1205, 1206 denote the first and second sealing materials thatcontain gap materials for maintaining a gap of an enclosed space,respectively.

The pixel portion 1202 and the scanning line driver circuit 1203 arepositioned inside a region sealed with the first and second sealingmaterials, while the signal line driver circuit 1230 is positionedoutside of the region sealed with the first and second sealingmaterials.

Next, a cross sectional structure will be described referring to FIG.13B. A driver circuit and a pixel portion are formed over the firstsubstrate 1200, which includes a plurality of semiconductor elementsrepresented by the TFTs. The signal line driver circuit 1230 that is oneof driver circuits is connected to a terminal on a layer 1210 with asemiconductor element formed therein. The pixel portion 1202 is providedon the first substrate. The signal line driver circuit 1230 is made froman IC chip using a single crystal silicon substrate. As substitute forthe IC chip using the single crystal silicon substrate, an integratedcircuit chip formed by a TFT can be used. The pixel portion 1202 and thescanning line driver circuit (not shown in FIG. 13B) are formed of TFTs.The pixel driving TFT and the scanning line driver circuit are formed ofinverted-stagger type TFTs, in the embodiment. A part or an entire ofrespective components for the inverted-stagger type TFTs can be formedby an ink-jet method, a droplet discharging method, the CVD method, thePVD method, and the like. A channel formation region of the TFT 1231 isformed of an amorphous semiconductor film, a microcrystallinesemiconductor film, or an organic semiconductor film.

The microcrystalline semiconductor film is formed by glow dischargedecomposition with silicide gas (plasma CVD). As for the silicide gas,SiH₄, Si₂H₆, SiH₂Cl₂, SiHCl₃, SiCl₄, SiF₄, and the like can be used. Thesilicide gas may also be diluted with H₂ or a mixture of H₂ and one ormore rare gas elements selected from the group consisting of He, Ar, Kr,and Ne. It is preferable that the dilution ratio be in the range of from1:2 to 1:1,000. The pressure may approximately be in the range of from0.1 Pa to 133 Pa. The power supply frequency is in the range of from 1MHz to 120 MHz, preferably, from 13 MHz to 60 MHz. The substrate heatingtemperature may be set to 300° C. or less, preferably from 100° C. to250° C. As for impurity elements contained in the film, eachconcentration of impurities for atmospheric constituents such as oxygen,nitrogen, and carbon is preferably set to 1×10²⁰/cm³ or less. Inparticular, the oxygen concentration is preferably set to 5×10¹⁹/cm³ orless; more preferably, 1×10¹⁹/cm³ or less. The fluctuation in theelectric characteristics of the TFTs can be reduced by using themicrocrystalline semiconductor film.

A light emitting element 1237 includes a first electrode 1233, a layer1235 containing a luminescent substance, and a second electrode 1236.The electrodes and layer are formed using the same materials andmanufacturing methods of Embodiment 3. The light emitting element iselectrically connected to a TFT 1231 via a wiring 1232. Various kinds ofsignals and potential applied to the scanning line driver circuit 1203and the pixel portion 1202 are supplied from an FPC 1209 via aconnection wiring 1208. The connection wiring 1208 and the FPC 1209 areelectrically connected to one another with an anisotropic conductivefilm or anisotropic conductive resin 1227.

A polarizing plate 1225 is provided on a surface of the second substrate1204 as well as Embodiment 3. A retardation plate 1229 of ½λ or ¼λ andan antireflection film 1226 are provided on the surface of thepolarizing plate 1225.

As set forth above, one feature of the light emitting display deviceaccording to the present embodiment is that the layer having theelements and the color filter are formed separately through thedifferent steps, and they are attached to each other after completion.According to the structure, the yield of the layer having the elements,i.e., the TFTs and the liquid crystal element and the yield of the colorfilter can be controlled individually, thereby suppressing reduction inthe yield of the entire light emitting display device.

Further, the steps of manufacturing an active matrix substrate and thesteps of manufacturing the color filter can run simultaneously, reducingthe manufacturing lead time for the light emitting display device.

In addition, since the plastic substrate is used, a lightweight lightemitting display device having an excellent impact resistance propertycan be manufactured.

Embodiment 5

Circuit diagrams of pixels for a light emitting display devicecorresponding to one embodiment of the invention will be described withreference to FIGS. 15A to 15C.

FIG. 15A shows an equivalent circuit diagram of a pixel, including asignal line 1514, a power supply lines 1515, 1517, a scanning line 1516,a light emitting element 1513, a TFT 1510 for controlling input of videosignals to the pixel, a TFT 1511 for controlling an amount of currentthat flows between electrodes, and a capacitor element 1512 for holdinga gate-source voltage. Although the capacitor element 1512 is shown inFIG. 15A, it may not be provided in the case where a gate capacitance orthe other parasitic capacitance can serve as a capacitor for holding thegate-source voltage.

FIG. 15B shows a pixel circuit having a structure in which a TFT 1518and a scanning line 1519 are additionally provided to the pixel shown inFIG. 15A. Supply of the current can be forcibly stopped due to thearrangement of the TFT 1518, thereby starting a lighting periodsimultaneously with or immediately after a writing period starts beforesignals are written in all of the pixels. Therefore, duty ratio isincreased, and in particular, moving image can be displayed preferably.

FIG. 15C shows a pixel circuit in which a TFT 1525 and a wiring 1526 areadditionally provided to the pixel shown in FIG. 15B. In this structure,a gate electrode of a TFT 1525 is connected to a wiring 1526 maintaininga constant potential so that the potential for the gate electrode isfixed. Further, the TFT 1525 is operated in a saturation region. The TFT1511 is connected to the TFT 1525 in series and operated in a linearregion. A gate electrode of the TFT 1511 is input with video signals fortransmitting information about lighting or non-lighting of the pixel viathe TFT 1510. Since the source-drain voltage for the TFT 1511 that isoperated in the linear region is low, slight variation in thegate-source voltage of the TFT 1511 does not adversely affect the amountof current flowing through the light emitting element 1513. Therefore,the amount of current flowing through the light emitting element 1513 isdetermined by the TFT 1525, which is operated in the saturation region.According to the invention having the above-mentioned structure,luminance fluctuation of the light emitting element 1513, which iscaused due to fluctuation in the characteristics of the TFT 1525, can beimproved, thereby improving the image quality. It is preferable that thechannel length L₁ and the channel width W₁ for the TFT 1525, and thechannel length L₂ and the channel width W₂ for the TFT 1511 be set so asto satisfy the relation of L₁/W₁: 5 to 6,000:1. It is also preferablethat the TFTs 1525 and 1511 comprise a same conductivity type from theviewpoint of the manufacturing steps. The TFT 1525 may be either anenhancement TFT or a depletion TFT.

In the light emitting display device of the invention, the method ofdriving screen display is not particularly limited. For example, a dotsequential driving method, a line sequential driving method, a surfacesequential driving method, and the like may be used. The line sequentialdriving method is typically used, and a time division gray scale drivingmethod or a surface area gray scale driving method may also be employedappropriately. Further, a source line of the light emitting displaydevice may be input with either analog signals or digital signals. Adriver circuit and the like may be designed properly according to theimage signals.

Light emitting display devices using digital video signals areclassified into one in which video signals are input to a pixel at aconstant voltage (CV), and another one in which video signals are inputto a pixel at a constant current (CC). The light emitting devices inwhich video signals are input to a pixel at a constant voltage (CV) arefurther classified into one in which a constant voltage is applied to alight emitting element (CVCV), and another one in which a constantcurrent is supplied to a light emitting element (CVCC). The lightemitting devices in which video signals are input to a pixel at aconstant current (CC) is still classified into one in which a constantvoltage is applied to a light emitting element (CCCV), and another onein which a constant current is supplied to a light emitting element(CCCC).

In the light emitting display device according to the invention, aprotection circuit (e.g., a protection diode and the like) may beprovided to the driver circuits or the pixel portion for the purpose ofinhibiting electrostatic discharge damage.

Embodiment 6

In the present embodiment, an exterior appearance of a liquid crystaldisplay device panel corresponding to one embodiment of a display deviceaccording to the invention will be explained with reference to FIGS. 16Aand 16B. FIG. 16A shows a tow view of a panel in which a first substratewith a semiconductor element formed thereon and a second substratehaving a color filter are attached to each other by using a firstsealing material 1605 and a second sealing material 1606. FIG. 16Bcorresponds to a cross sectional view taken along a line A-A′ of FIG.16A.

In FIG. 16A, reference numeral 1601 denoted by a dotted line representsa signal line driver circuit; 1602, a pixel portion; and 1603, ascanning line driver circuit. In the present embodiment, the signal linedriver circuit 1601, the pixel portion 1602, and the scanning linedriver circuit 1603 are provided inside a region sealed with the firstand second sealing materials.

Further, reference numeral 1600 denotes the first substrate; and 1604,the second substrate. Reference numerals 1605 and 1606 represent thefirst and second sealing materials, respectively, that contain a gapmaterial for maintaining a gap of an enclosed space. The first substrate1600 and the second substrate 1604 are attached to each other with thefirst and second sealing materials 1605; 1606, and a liquid crystalmaterial is filled therebetween.

A cross sectional structure will be described referring to FIG. 16B.Driver circuits and a pixel portion are formed on the first substrate1600 along with plural semiconductor elements typified by a TFT. A colorfilter 1621 is provided on a surface of the second substrate 1604. Asubstrate 914 having the color filter, which is formed according toEmbodiment 2 (i.e., the second substrate 1604 and the color filter 1621provided thereon), can be used. The signal line driver circuit 1601 andthe pixel portion 1602 are illustrated as the driver circuits. Thesignal line driver circuit 1601 is formed of a CMOS circuit incombination of an n-channel TFT 1612 and a p-channel TFT 1613.

The TFTs of the signal line driver circuit, the scanning line drivercircuit, and the pixel portion are formed on the same substrate in thepresent embodiment so that volume of the panel can be reduced.

A plurality of pixels is formed in the pixel portion 1602, and a liquidcrystal element 1615 is formed in each pixel. The liquid crystal element1615 indicates a region overlapping a first electrode 1616, a secondelectrode 1618, and a liquid crystal material 1619, which is filledbetween the first and second electrodes, with one another. The firstelectrode 1616 of the liquid crystal element 1615 is electricallyconnected to the TFT 1611 via the wiring 1617. The second electrode 1618of the liquid crystal element 1615 is formed on a side of the secondsubstrate 1604, that is, on the color filter 1621. Note that alignmentfilms are formed on each surface of respective pixel electrodes, thoughnot shown in the drawing.

Reference numeral 1622 represents a columnar spacer that is provided tomaintain a distance (cell gap) between the first electrode 1616 and thesecond electrode 1618. The spacer is formed by etching an insulatingfilm into a predetermined shape. Alternatively, a spherical spacer maybe employed. Various kinds of signals and potential are applied to thesignal line driver circuit 1601 and the pixel portion 1602 from an FPC1609 via a connection wiring 1623. The connection wiring 1623 and theFPC are electrically connected to one another with an anisotropicconductive film or anisotropic conductive resin 1627. Note that aconductive paste such as solder may be used in place of the anisotropicconductive film or anisotropic conductive resin.

A polarizing plate 1625 is fixed to the surface of the second substrate1604 with an adhesive material 1624. A circular polarizing plate or anelliptical polarizing plate provided with a retardation plate may beused as the polarizing plate 1625. A retardation plate of ½λ or ¼λ, andan antireflection film 1626 are provided on the surface of thepolarizing plate 1625. Similarly, the surface of the first substrate1600 is provided with a polarizing plate (now shown) with an adhesivematerial.

According to the embodiment, a liquid crystal display device having anoptical film with a plastic substrate can be fabricated. As aconsequence, a lightweight, thin liquid crystal display device having anexcellent impact resistance property can be manufactured. In addition, adisplay device having a curved surface and a liquid crystal displaydevice that can be varied in shape can be manufactured.

Embodiment 7

In the present embodiment, an exterior appearance of a panelcorresponding to one embodiment of a display device according to theinvention will be explained with reference to FIGS. 17A and 17B. FIG.17A shows a tow view of a panel in which a first substrate with asemiconductor element formed thereon and a second substrate having acolor filter are attached to each other by using a first sealingmaterial 1605 and a second sealing material 1606. FIG. 17B correspondsto a cross sectional view taken along a line A-A′ of FIG. 17A. Anexample in which a signal line driver circuit using an IC chip ismounted on the panel is shown here.

In FIG. 17A, reference numeral 1630 represents a signal line drivercircuit; 1602, a pixel portion; and 1603, a scanning line drivercircuit. Further, reference numeral 1600 denotes the first substrate;and 1604, the second substrate. Reference numerals 1605 and 1606represent the first and second sealing materials, respectively, thatcontain a gap material for maintaining a cell gap of an enclosed space.

The pixel portion 1602 and the scanning line driver circuit 1603 areprovided inside a region sealed with the first and second sealingmaterials; while the signal line driver circuit 1630 is provided outsideof the region sealed with the first and second sealing materials. Thefirst and second substrates 1600, 1604 are attached to each other withthe first and second sealing materials 1605, 1606, and a liquid crystalmaterial is filled therebetween.

Next, a cross sectional structure will be described referring to FIG.17B. A driver circuit and a pixel portion are formed over the firstsubstrate 1600, which includes a plurality of semiconductor elementsrepresented by a TFT. The signal line driver circuit 1630 that is one ofthe driver circuits is connected to a terminal on the layer 1610 withthe semiconductor element formed therein. The pixel portion 1602 isprovided over the first substrate. The signal line driver circuit 1630is made from an IC chip suing a single crystal silicon substrate. Assubstitute for the IC chip using the single crystal silicon substrate,an integrated circuit chip formed of a TFT can be used. The pixelportion 1602 and the scanning line driver circuit (not shown in FIG.17B) are formed of the TFTs. In the present embodiment, a pixel drivingTFT and a scanning line driver circuit are formed of inverted-staggertype TFTs, which are made from amorphous semiconductor films ormicrocrystalline semiconductor films.

A first electrode 1616 of the liquid crystal element 1615 iselectrically connected to a TFT 1631 via a wiring 1632 in the samemanner as Embodiment 6. A second electrode 1618 of the liquid crystalelement 1615 is formed on the second substrate 1604, i.e., on the colorfilter 1621. Reference numeral 1622 represents a columnar spacer, and isprovided for maintaining the distance (cell gap) between the firstelectrode 1616 and the second electrode 1618. Various kinds of signalsand potential are applied to the scanning line driver circuit 1603 andthe pixel portion 1602 from an FPC 1609 via a connection wiring 1623.The connection wiring 1623 and the FPC are electrically connected to oneanother with an anisotropic conductive film or anisotropic conductiveresin 1627.

A polarizing plate 1625 is fixed on the surface of the second substrate1604 with an adhesive material 1624 in the same manner as Embodiment 6.A retardation plate 1629 of ½λ or ¼λ and an antireflection film 1626 areprovided on the surface of the polarizing plate 1625.

According to the embodiment, a liquid crystal display device having anoptical film with a plastic substrate can be fabricated. As aconsequence, a lightweight, thin liquid crystal display device having anexcellent impact resistance property can be manufactured. Additionally,a display device having a curved surface and a display device that canbe varied in shape can be manufactured.

Also, since a plastic substrate is used, a lightweight liquid crystaldisplay device having an improved impact resistance property can befabricated.

Embodiment 8

Various kinds of electronic appliances can be manufactured by beingincorporated with a display device formed according to the presentinvention. Examples of the electronic appliances include: a TV set; avideo camera; a digital camera; a goggle type display (a head-mounteddisplay); a navigation system; an audio reproduction device (such as acar audio and an audio component system); a personal laptop computer; agame machine; a portable information terminal (such as a mobilecomputer, a cellular telephone, a portable game machine, and anelectronic book); an image reproduction device provided with a recordingmedium (typically, a device which can reproduce the recording mediumsuch as a digital versatile disc (DVD) and display images thereof); andthe like. As representative examples of these electronic appliances, ablock diagram and a perspective view of a television are shown in FIG.18 and FIG. 19, respectively, while perspective views of a digitalcamera are shown in FIGS. 20A and 20B.

FIG. 18 shows a general structure of a television receiving analogtelevision broadcasting. In FIG. 18, the airwaves for televisionbroadcasting received by an antenna 1101 are input in a tuner 1102. Thetuner 1102 generates and outputs intermediate frequency (IF) signals bymixing the high frequency television signals input by the antenna 1101and locally-oscillating frequency signals that are controlled inaccordance with the predetermined reception frequency.

The IF signals output from the tuner 1102 are amplified up to therequired amount of voltage by an intermediate frequency amplifier (IFamplifier) 1103. Thereafter, the amplified IF signals are detected by animage detection circuit 1104 and an audio detection circuit 1105. Thesignals output from the image detection circuit 1104 are divided intoluminance signals and color signals by an image processing circuit 1106.Further, the luminance signals and the color signals are subjected tothe predetermined image signal processing to become image signals sothat the image signals are output to an image output unit 1108 such as aCRT, a LCD, and an EL display.

The signals output from the audio detection circuit 1105 are subjectedto processing such as FM demodulation in an audio processing circuit1107 to become audio signals. The audio signals are then amplifiedarbitrarily so as to be output to an audio output unit 1109 such as aspeaker.

The television according to the present invention may be applicable todigital broadcastings such as digital terrestrial broadcasting, cabledigital broadcasting, and BS digital broadcasting, besides analogbroadcastings such as regular broadcasting in VHF band, in UHF band,etc., cable broadcasting, and BS broadcasting.

FIG. 19 shows a perspective view seen from the front of the television,including a housing 1151; a display portion 1152; speaker units 1153; anoperational portion 1154; a video input terminal 1155; and the like. Thetelevision shown in FIG. 19 includes the structure as shown in FIG. 18.

The display portion 1152 is an example of the image output unit 1158 inFIG. 18, and displays images.

The speaker units 1153 are examples of the audio output unit in FIG. 18,and output sounds therefrom.

The operational portion 1154 is provided with a power source switch, avolume switch, a channel select switch, s tuning switch, a selectionswitch, and the like, so as to turn on and off the television, selectimages, control sounds, select tuner, and the like, respectively. Notethat above-mentioned selections can be carried out by using an operationunit of a remote controller, though not illustrated in the drawing.

The video input terminal 1155 inputs image signals into the televisionfrom an external portion such as a VTR, a DVD, and a game machine.

In the case of a wall-hanging television, a wall-hanging portion isprovided on the rear of the body thereof.

By utilizing the display device of the invention to the display portionof the television, a thin, lightweight television having an excellentimpact resistance property can be manufactured. Therefore, suchtelevision is widely applicable to a wall-hanging television, inparticular, to large-size display mediums such as information displayboards used in railway stations, airports, etc., and advertisementdisplay boards on the streets.

Next, an example in which the display device manufactured according tothe invention is applied to a digital camera will be described withreference to FIGS. 20A and 20B.

FIGS. 20A and 20B are diagrams showing an example of the digital camera.FIG. 20A shows a perspective view seen from the front of the digitalcamera, while FIG. 20B shows a perspective view seen from the rearthereof: In FIG. 20A, reference numeral 1301 represents a releasebutton; 1302, a main switch; 1303, a viewfinder window; 1304, flash;1305, a lens; 1306, a lens barrel; and 1307, a housing.

In FIG. 20B, reference numeral 1311 represents a viewfinder eyepiece;1312, a monitor; and 1313, an operational button.

Upon depressing the release button 1301 halfway, a focus adjustmentmechanism and an exposure adjustment mechanism are operated.Subsequently, depressing the release button all the way releases ashutter.

The digital camera is turned on and off by pressing or rotating the mainswitch 1302.

The viewfinder window 1303 is disposed above the lens 1305 in the frontface of the digital camera, and a shooting range and a focusing pointare checked through the viewfinder eyepiece 1311 as shown in FIG. 20Band the viewfinder window.

The flash 1304 is disposed at the top of the front face of the digitalcamera body. In the case of photographing a subject of the low luminancelevel, after depressing the release button, the shutter is released totake the picture simultaneously with flushing a light.

The lens 1305 is attached to the front of the digital camera. The lensis made of a focusing lens, a zoom lens, and the like. An opticalshooting system includes the lens along with a shutter and an aperture,which are not illustrated in the drawing.

The lens barrel 1306 is used for shifting the lens position so as tofocus the focusing lens, the zoom lens, and the like on a subject. Totake the picture, the lens barrel protrudes from the body so that thelens 1305 is shifted toward a subject. When carrying the digital camera,the lens 1305 is stored inside the main body to be reduced in size.Although the lens can be zoomed in to enlarge a subject by shifting thelens barrel in the present embodiment, the present invention is notlimited to the structure. The invention can be applicable to a digitalcamera that can take close-up pictures without zooming a lens due to astructure of an optical shooting system inside the housing 1307.

The viewfinder eyepiece 1311 is provided at the top portion of the rearof the digital camera, through which the shooting range and the focusingpoint are checked by sight.

The operational button 1313 represents a button with various kinds offunctions and is provided on the rear of the digital camera. Theoperational button include a setup button, a menu button, a displaybutton, a functional button, a selection button, and the like.

By utilizing the display device of the invention to a monitor of thedigital camera, a thinner, portable digital camera can be manufactured.

The present invention has been fully described by way of embodimentmodes and embodiments with reference to the accompanying drawings. Notethat it should be understood to those skilled in the art that thepresent invention can be embodied in several forms, and the modes andits details can be changed and modified without departing from thepurpose and scope of the present invention. Accordingly, interpretationof the present invention should not be limited to descriptions mentionedin the foregoing embodiment modes and embodiments. Note that portionsidentical to each other are denoted by same reference numerals in theaccompanying drawings for the sake of convenience.

What is claimed is:
 1. A method of manufacturing a light emittingdevice, comprising steps of: forming an optical filter over a firstsubstrate; forming a transistor and a light emitting elementelectrically connected to the transistor over a second substrate;attaching the optical filter and the light emitting element using afirst adhesive material; separating the first substrate from the opticalfilter; and separating the second substrate from the transistor.
 2. Themethod according to claim 1, wherein the step of attaching the opticalfilter and the light emitting element using the first adhesive materialis performed after separating the first substrate from the opticalfilter.
 3. The method according to claim 1, wherein the step ofattaching the optical filter and the light emitting element using thefirst adhesive material is performed before separating the secondsubstrate from the transistor.
 4. The method according to claim 1,wherein the light emitting element emits white light.
 5. The methodaccording to claim 1, wherein the optical filter is a color filter andthe color filter comprises at least one of red, blue, and green coloredlayers.
 6. The method according to claim 1, wherein the optical filteris a color filter and the color filter further comprises a black matrixadjacent to the one of red, blue, and green colored layers.
 7. A methodof manufacturing a light emitting device, comprising steps of: formingan optical filter over a first substrate; forming a transistor and alight emitting element electrically connected to the transistor over asecond substrate; attaching the optical filter and the light emittingelement using a first adhesive material; separating the first substratefrom the optical filter; attaching a first flexible substrate to theoptical filter using a second adhesive material after the step ofseparating the first substrate; separating the second substrate from thetransistor; and attaching a second flexible substrate to the transistorusing a third adhesive material after the step of separating the secondsubstrate.
 8. The method according to claim 7, wherein the step ofattaching the optical filter and the light emitting element using thefirst adhesive material is performed after separating the firstsubstrate from the optical filter.
 9. The method according to claim 7,wherein the step of attaching the optical filter and the light emittingelement using the first adhesive material is performed before separatingthe second substrate from the transistor.
 10. The method according toclaim 7, wherein the first adhesive material comprise a first sealingmaterial and a second sealing material and wherein the first sealingmaterial is provided along a periphery of the first flexible substrateand surrounding the second sealing material.
 11. The method according toclaim 7, wherein the first flexible substrate is a plastic substratecomprising polyimide.
 12. The method according to claim 7, wherein thelight emitting element emits white light.
 13. The method according toclaim 7, wherein the optical filter is a color filter and the colorfilter comprises at least one of red, blue, and green colored layers.14. A method of manufacturing a light emitting device, comprising stepsof: forming a first oxide film over a first substrate; forming anoptical filter over the first oxide film; forming a second oxide filmover a second substrate; forming a transistor and a light emittingelement electrically connected to the transistor over the second oxidefilm; attaching the optical filter and the light emitting element usinga first adhesive material; separating the first substrate from the firstoxide film; attaching a first flexible substrate to the first oxide filmusing a second adhesive material after the step of separating the firstsubstrate; separating the second substrate from the second oxide film;and attaching a second flexible substrate to the second oxide film usinga third adhesive material after the step of separating the secondsubstrate.
 15. The method according to claim 14, wherein the step ofattaching the optical filter and the light emitting element using thefirst adhesive material is performed after separating the firstsubstrate from the first oxide film.
 16. The method according to claim14, wherein the step of attaching the optical filter and the lightemitting element using the first adhesive material is performed beforeseparating the second substrate from the second oxide film.
 17. Themethod according to claim 14, wherein the first oxide film and thesecond oxide film comprises silicon oxide.
 18. The method according toclaim 14, wherein the first adhesive material comprise a first sealingmaterial and a second sealing material and wherein the first sealingmaterial is provided along a periphery of the first flexible substrateand surrounding the second sealing material.
 19. The method according toclaim 14, wherein the first flexible substrate is a plastic substratecomprising polyimide.
 20. The method according to claim 14, wherein thelight emitting element emits white light.
 21. The method according toclaim 14, wherein the optical filter is a color filter and the colorfilter comprises at least one of red, blue, and green colored layers.